On June 10, 1999, after 78 days of a US-led NATO bombing campaign, the Serbian army withdrew from Kosovo, a small province with an ethnic-Albanian majority. But with the Serbian Army's eviction, the ethnic-Serb dominated government in Kosovo collapsed. To take its place, and oversee Kosovo's physical and political reconstruction, the Security Council created the United Nations Interim Mission in Kosovo, UNMIK, that very day.

From the outset, a large NATO force in Kosovo obviated the need for a significant deployment of UN peacekeepers. The United Nations, however, provided the bulk of international civilian administrators and supplied a "blue hat" police force, which has played a crucial role in Kosovo's reconstruction.

As envisioned by the Security Council resolution, Kosovo's physical and political reconstruction would be built upon on four "Pillars." The Organization for Security and Cooperation in Europe would oversee democratization and institution building. The European Union would spearhead economic development. The United Nations was left with the difficult task of setting up a judicial system and polices services, while a UN representative would serve as the top civilian administrator. UNMIK would remain operational until Kosovo's final status--either as a sovereign state, province of Serbia, or something in between--was decided.

Setting up a functioning police force was a particularly difficult task. When Serbian forces left Kosovo, the police force--which was aligned with Serbian President Slobodan Milosevic--disintegrated. The job of maintaining law and order through basic police work like investigating crimes and traffic control fell to the United Nations.

Their most important task, though, was hiring and training local police. In 2004, the Kosovo Police Service reached its planned size of nearly 7,000 officers. Today, there are fewer than 2,000 UN Police in Kosovo, reflecting the fact that the Kosovo Police Service is now up and running.

Meanwhile, uncertainty over Kosovo's final status remains a constant challenge to the mission. In March 2007, Martti Ahtisaari, the UN's top diplomat for the "future status process" recommended the province's independence from Serbia. Russia, a traditional ally of Serbia, balked at this suggestion. Should the debate in the Security Council remain intractably stalled, Kosovo's ethnic Albanian government may unilaterally declare independence from Serbia. If that happens, European governments could be split over whether or not to formally recognize Kosovo, which could potentially threaten the flow of funds for Kosovo's reconstruction.

Until questions about Kosovo's final status are resolved, UNMIK will likely stay put and continue to help the fragile Kosovo government assume greater administrative control over its territory.

Though far from the television screens of most Americans, some of the fighting in Ethiopia and Eritrea resembles a war with which they might be familiar. At its peak, hundreds of kilometers of trenches snaked their way around the border region of the two neighboring countries in the Horn of Africa, raising frequent comparisons to World War One. And like World War One, the toll of the trench warfare on conscripts has been exacting. Though no one knows for sure, 70,000 people are estimated to have been killed. There have also been as many as 700,000 displaced or made refugees from the war, which at one point cost these desperately impoverished countries $1 million a day to sustain.

For most of the 20th century, Eritrea, the smaller of the two countries, was a province of Ethiopia. After a long struggle, it gained independence in 1993. But the precise borders were never demarcated. One desolate region in particular, Badme, was a persistent point of contention. In May 1998, Eritrean fighters skirmished with the local Ethiopian-aligned forces there. Ethiopia's response was swift and both countries sent massive numbers of troops and artillery to the border region. Soon, 300,000 soldiers were staring at each other along an 800 kilometer trench line.

In May 2000, then-United States National security advisor Anthony Lake helped oversee international and regional efforts to end the conflict. In June 2000, both sides signed the Algiers Peace Agreement, ceasing hostilities. The Security Council then authorized the deployment of over 4,000 peacekeepers to the newly formed United Nations Mission in Ethiopia and Eritrea (UNMEE) to patrol the border region.

As part of the Algiers agreement, the two sides agreed to let a neutral commission determine the official boundaries. Two years later, the commission, in collaboration with the Permanent Court of Arbitration in the Hague awarded Badme to Eritrea. Other disputed territories went to Ethiopia and the two sides agreed to abide by the verdict. Ethiopia began withdrawing troops from the frontier and UNMEE began to scale back its presence. However, all was not well. In 2004, Ethiopia disputed the boundary ruling and deployed tens of thousands of troops to the border region, including Badme. A frustrated Eritrea expelled UNMEE troops from certain counties and restricted UN helicopter flights. A seemingly intractable stalemate persists to this day.

In May 2006, with its movements restricted, UNMEE was forced to downsize. Today, there are only 1,700 UNMEE troops patrolling the region, and one of their most important tasks is locating and disposing of the estimated 3 million landmines that dot the border region.

The Security Council has threatened both sides with sanctions, but the situation remains volatile. At this point, the main goal of international diplomacy is to force both sides to agree to the terms of the Algiers Agreement, including the border demarcations authorized by the Court of Permanent Arbitration. This is no easy task, but the alternative is an unstable stalemate that could once again flare into brutal warfare.

When the United Nations is responsible for birthing a new country, as it was in East Timor over the past eight years, one can be forgiven for being a touch confused by the alphabet soup of UN missions involved.

Please bear with me: Following an East Timor referendum on independence from Indonesia in 1999, UNAMET was replaced by UNTAET, which in turn became subsumed into UNMISET and later transitioned into UNOTIL, that is, until 2006 when UNMIT -- the United Nations Mission in East Timor -- took over. For those less versed in UN-ease, let me explain.

East Timor, or Timor Leste as it is formally known in the UN system, is a tiny country situated on the eastern shores of the Indonesian archipelago. It stands today as an example of a country that was nurtured into existence and then protected at birth by the United Nations. Observers have hailed East Timor as a nation-building success story, but it is clear that East Timor is still a work in progress.

The conflict in East Timor draws its roots from Portugal's abrupt decision in 1974 to abandon East Timor, a territory it had colonized for centuries. Just days following the Portuguese withdrawal, the Indonesian government moved forces into East Timor, claiming that a communist movement threatened to spill over into Indonesia itself. So began a quarter-century of terrible suffering for the people of East Timor. An estimated 100,000 to 200,000 people are believed to have been killed in the 25 years of Indonesian occupation.

In 1999, under international pressure, Indonesian president BJ Habbibie acceded to a referendum that would let East Timor decide on independence from Indonesia. The Security Council then created UNAMET, the first of five UN missions in East Timor, to administer the elections.

On August 30, East Timor voted overwhelmingly for independence. But following the elections, the Indonesian military and pro-Indonesian militias instigated riots and violence soon spread out of control. The Security Council quickly approved an Australian-led international force that was able to stem the violence. By October 1999 a new international police force, UNATET, was authorized to keep the peace as East Timor prepared for national elections.

In 2002, East Timor voted for a president and parliament. The country, however, remained fragile, and the new government asked the United Nations to approve a new peacekeeping mission, UNMISET, to help provide security as the fledgling democracy built itself from scratch. By August there were nearly 5,000 UN peacekeepers in East Timor. The United Nations, meanwhile, welcomed a new member to the family. On September 27, the General Assembly voted unanimously to make East Timor the UN's 191st member state.

In May 2005, UNMSET closed its doors and the peacekeeping mission was replaced with UNOTIL, a political mission to support the development of the nation's infrastructure and state institutions. Still, all was not well in Dilli, East Timor's capital. In April 2006, a rally in support of East Timorese soldiers who were fired for desertion turned into a violent riot. Many were killed and an estimated 100,000, one tenth of the population, fled their homes. The crisis threatened to undermine seven years of UN and Timorese efforts to rebuild their country. Once again, Australia led an international intervention to restore order in the country. The Security Council, meanwhile, approved yet another mission, one that exists to this day.

Today, there over 1,600 uniformed personnel, mostly police, deployed in the United Nations Mission in East Timor, UNMIT. They support state institution and capacity building and helped oversee recent presidential elections, which concluded on Sunday when East Timor's newest president, the Nobel Laureate Jose Ramos Horta, assumed office. UNMIT is scheduled to conclude in February 2008. But prior to that, the Security Council may decide to reauthorize UNMIT for another year to make sure that East Timor is on stable footing.

The Democratic Republic of Congo (DRC) is the largest and most expensive peacekeeping operation in the world. As of March, there were 18,336 total uniformed personnel, including 16,594 troops, 713 military observers, and 1,029 police, costing over $1 billion per year. But the price of peace is still less than the cost of years of war in Congo, which claimed more lives than any other conflict since World War Two.

From 1998 to 2003 nearly 4 million people are thought to have perished in a civil war stoked by Congo's neighbors. Today, that fighting has largely, but not completely, subsided. And while it is too early to call the DRC a UN Peacekeeping success story, it is clear that the United Nations Mission in the Congo (called by its French acronym, MONUC) is responsible for overseeing Congo's significant strides toward peace and democracy in recent years.

For 37 years Mobutu Sesse Seko ruled Congo (then called Zaire) by enriching himself and impoverishing his citizens. Laurent Kabila, a rebel leader supported by some of Congo's neighbors, overthrew Mobutu in 1997. The country soon plunged into brutal civil war, with various armed factions sometimes serving as proxies for Congo's nine neighboring countries. In early 2001, the 29 year old Joseph Kabila assumed the presidency following his father's assassination. Kabila the younger soon made significant efforts toward a comprehensive regional peace process, which became formalized in a 2003 agreement.

To prevent spoilers from undermining the agreement, the Security Council authorized a deployment of peacekeepers. (The United Nations has a long history in Congo. Secretary General Dag Hammarskjold died in a plane crash while en route to negotiate a ceasefire in Congo back in 1961.) This newest round of UN intervention began in 1999 when MONUC military observers were deployed to monitor a nominal ceasefire agreement between Congo, a rebel movement within Congo, and five of Congo's neighbors. In 2001, the Security Council expanded MONUC to 3,600 peacekeepers. The fighting, however, continued. In the north-eastern province Ituri, the fighting bordered on genocide, sparking the Security Council to dramatically expand the number of troops deployed there. Soon, there were over 10,000 troops in the DRC, many in Ituri.

These peacekeepers face grueling tasks. The country is the size of Western Europe, with few roads to support armored personnel carriers and other heavy military equipment. There were some setbacks. In 2004, an armed group overran UN forces and took over the town of Bukavu, killing many residents and looting their possessions. In response, the Security Council reinforced MONUC with additional 6,000 troops and expanded its mandate to ensure civilian protection. A newly emboldened Monuc force in Ituri began to experiment with more assertive peacekeeping tactics. Rather than simply provide protection to civilians and humanitarian workers, peacekeepers in Ituri sought to roll back militias by in aggressive tactical raids.

By 2005, MONUC's most important task was deterring spoilers from undermining national elections planned for 2006. These elections, which took place in late July, were a logistical accomplishment of historical proportions. The United Nations registered some 25 million people throughout the country. Ballots were transported by truck, plane, helicopter and even canoe. 80% of the population voted, and after a runoff selected Joseph Kabila. For the first time in 40 years, the Congolese people had voted for in a multiparty election.

After years of war, the DRC remains a broken country. It consistently ranks near the top of Foreign Policy's failed states index. Kabila's government is unable to deliver basic services to most of its citizens and depends on foreign assistance. The largest, most expensive, and most accomplished peacekeeping mission in the world, however, continues to offer the Congolese people a blanket of protection while democracy takes root.

Ten years ago, I would have sounded crazy should I have predicted that Liberia would become a functioning democracy by 2007, and that Charles Taylor, the Liberian warlord turned president, would be in jail awaiting prosecution for war crimes. And rightly so -- in 1997, Liberia was a singularly dismal place on earth. Taylor had just been elected president after leading a bloody insurgency characterized by the recruitment of child soldiers, wide-spread rape and mutilation. Taylor's popular support, however, was less from admiration than fear. Prior to the election, throngs on the street chanted, "He killed my ma, he killed my pa, I'm going to vote for him!" Better to vote him president than have him lose the election and turn his wrath against the people.

For the previous eight years, the civil war in Liberia had claimed the lives of 150,000 people and displaced 850,000 to neighboring countries. The illegal trade of diamonds and other natural resources abundant in Liberia fueled the civil war, and helped fund Taylor's regime. In 1999 a new round of fighting erupted when a rebel movement backed by Guinea took hold in northern Liberia. In early 2003, separate rebel movement from the south emerged. By the summer, the rebels had gained considerable strength and were threatening Monrovia, Liberia's densely populated capital.

So began a series of events that eventually led to Taylor's ouster. The United States diverted a ship carrying 1,500 marines heading toward the Persian Gulf and stationed it just outside of Monrovia. And just as the Marines were arriving to Liberia's shore, a United Nations war crimes tribunal in Sierra Leone issued an arrest warrant for Taylor, whose forces are alleged to have committed crimes against humanity during the neighboring country's own civil war. Then, on August 1, the Security Council authorized a multinational force for Liberia. With a detachment of marines just off shore -- and Nigerian troops en route to Monrovia -- President Bush joined regional leaders and called for Taylor to leave Liberia. On August 11, following a second suggestion from President Bush that Taylor exit Liberia, he fled to exile in Nigeria.

After terrorizing West Africa for over a decade, Taylor was finally dislodged from power. His successor entered into a peace agreement with the rebels that established a transitional government and paved the way for free elections. By the end of the summer, the Nigerian-led multinational force became an official UN peacekeeping operation to assist in the implementation of the peace agreement and deny spoilers an opportunity to plunge Liberia back into chaos. Years of sanctions left the economy in ruins and rampant corruption meant that state services and infrastructure were virtually non-existent. The newly formed United Nations Assistance Mission in Liberia (UNMIL) provided security guarantees that let the United Nations and other international agencies embark on a series of humanitarian and infrastructure building projects throughout the country.

In 2006, Liberians elected lead Ellen Johnson-Sirleaf, Africa's first female head of state. Soon after winning election (to well deserved international fanfare) Sirleaf formally requested Taylor's extradition from Nigeria to face the war crimes tribunal in Sierra Leone. Today, Taylor is in a jailhouse in The Hague awaiting his trial. Liberia, meanwhile, is steadily moving forward. The 15,000 strong UNMIL (which includes the UN's first all female police unit) is overseeing the disarmament and demobilization of former fighters, and helping UN and international agencies restore basic services to the Liberian people. Key to Liberia's progress is opening its abundant natural resources up to international trade. To that end, in May 2007, the Security Council lifted sanctions on the Liberian diamond trade, which for most of the country's history had been a source of misery, rather than prosperity for the Liberian people.

Despite Liberia's significant accomplishments post-Taylor, the state is still fragile. Over 250,000 people were killed in the conflicts. Considering that the population of Liberia is only slightly over 3 million that is a staggering percentage of the population. State infrastructure remains in ruins and Liberians continue to depend on the United Nations and other international agencies continue to deliver key services. Still, considering Liberia's significant progress from where it was just 10 years ago, it is clear that the country is on a hopeful path.

Two steps are generally required to stop an on-going conflict through diplomacy at the United Nations. When combatants become convinced that they have more to gain from peace than continued fighting, some sort of cease-fire agreement can be brokered. Then, once the parties agree to a ceasefire, the United Nations can put into place mechanisms to enforce the ceasefire. While the former depends on political will of the Security Council, the achieving the latter often requires the skill of diplomats in the General Secretariat.

In the summer of 2006, this process was on full display when the United Nations worked out a ceasefire between Israel and militant forces in Lebanon.

On July 12, Hezbollah militants killed eight Israeli soldiers stationed near the Lebanon-Israel border and captured two others. The Israeli Defense Forces retaliated with incursions into southern Lebanon and bombed targets throughout the country. Hundreds of thousands of civilians in the region were displaced as Hezbollah rockets rained down on northern Israel and Israeli bombs rocked southern Lebanon.

After thirty four calamitous days the parties to the conflict agreed to a ceasefire negotiated through the Security Council. Resolution 1701, which passed unanimously, called for the cessation of hostilities, the withdrawal of Israeli forces from Lebanese soil, and the deployment of a large peacekeeping force to help the Lebanese national army exert control over southern Lebanon. However, out of expediency the resolution left some key issues for later negotiations. The ceasefire held, but conditions on the ground remained deeply volatile. Resolving these outstanding problems required the intervention of someone regarded as an honest broker.

With historic powers unable or unwilling to step up, Secretary General Kofi Annan embarked on a frantic shuttle diplomacy to shore up the resolution. In eleven days, Annan traveled to Belgium, Lebanon, Israel, the Palestinian Territories, Jordan, Syria, Qatar, Iran, Saudi Arabia, Egypt, Turkey and Spain. He faced the daunting task of convincing regional actors to support the ceasefire. Further, Israel had insisted that it would only withdraw troops from Lebanon and lift its sea and air blockades once a peacekeeping force was in place. This did not sit well with Lebanese President Fouad Sinora, who was eager to see it lifted. A credible peacekeeping mission needed to be deployed--and it needed to happen fast.

The United Nations has had a peacekeeping force deployed to Lebanon in some form since 1978. Per the Security Council resolution, the United Nations Interim Force in Lebanon (UNIFIL) was to be drastically expanded and given a new mandate. But as with every peacekeeping mission, it is up to member states to actually contribute the troops. Convincing member states to commit troops, and then setting up the logistics of the actual deployment is often a laborious task. To complicate matters, Israel demanded that the peacekeepers only come from countries that have sophisticated military capabilities and diplomatic relations with Israel. But in the interest of balance, local sensitivities, and to avoid the appearance that UNIFIL would be an occupying force, the peacekeepers would have to be complimented by soldiers from Muslim countries as well. These political demands left precious few countries from which to draw troops.

In the end, France and Italy contributed the bulk of peacekeepers to UNIFIL. While in Ankara, Annan was also able to convince Turkey, which has relations with Israel, to contribute to the force. And following Annan's trip to Jerusalem, the Israeli government softened its position and consented to Indonesian contributions to UNIFIL. (Indonesia does not have formal relations with Israel.) During the trip, Annan was also able to orchestrate the lifting of the Israeli blockade. Working the phones, he secured French and German commitments to patrol the Lebanese coast and serve as border control agents at Lebanese airports. This is particularly significant because Germany, for historical reasons, has been reluctant to deploy troops to peacekeeping missions involving Israel.

Within weeks of Annan's trip, the first contingent of peacekeepers set foot in Lebanon. In fact, between the resolution and the deployment, only seventeen days lapsed, a remarkably fast deployment. This shows that when the political will is there, peacekeeping missions can get off the ground quickly. Today, there are currently over 13,000 uniformed personnel in Unifil. They continue to augment the Lebanese National Army in southern Lebanon. Troops also support other UN initiatives throughout Lebanon, such as removing unexploded ordinances, rebuilding and other humanitarian efforts.

Thanks to the quick intervention of the Secretary General, backed by crucial political support of member states, the ceasefire still holds in Southern Lebanon. Now the major task before the international community is to help establish a lasting comprehensive peace in the region.

These days, when one hears about a bloodbath in Sudan thoughts immediately drift to Darfur, Sudan's beleaguered western region where an estimated 200,000-400,000 people have died since the outbreak of civil war four years ago. However, as horrific as that number is, it pales in comparison to the carnage visited upon South Sudan for most of the last twenty years.

Sudan is an enormous territory with a relatively week central government. In 1983, the government in Khartoum tried to impose a harsh version of Islamic law over all of Sudan. The mostly Christian and animist provinces to the south rebelled. Four years later a new government began peace talks with the south. But then, in July 1989, a Sudanese Army General named Omar al Bashir, backed by the hard-line National Islamic Front (NIF), took power in a coup. Top among Bashir and the NIF's grievances was the previous government's progress toward a peace agreement with the south.

With Bashir in power, the civil war entered a new and deadlier phase. Using tactics that would foreshadow the enlistment of the janjaweed proxy militias in Darfur, Bashir and the NIF exploited existing ethnic tensions in southern Sudan--to brutal effect. In 1994 a Human Rights Watch report cited indiscriminate bombings, summary executions, and starvation as having claimed the lives of 1.3 million people in southern Sudan. The death toll continued to rise in Southern Sudan through out the 1990s, making it one of the worst man-made humanitarian disasters in the world; an estimated two million people died in nearly twenty years of fighting.

In 2001, the new American Presidential administration breathed fresh life into peace talks between Khartoum and the South. President Bush assigned former Senator John Danforth as his personal envoy to Sudan and made ending the long civil war a foreign policy priority. The United Nations and donor countries like Norway also played a significant role in these efforts, which resulted in the Comprehensive Peace Agreement (CPA), signed on January 9, 2005. The following day, the Security Council approved a peacekeeping deployment to southern Sudan to support the young agreement.

Today, there are little over 10,000 uniformed personnel in the United Nations Mission in Sudan (UNMIS), including 8,766 troops, 599 military observers, and 662 police. The deployment monitors ceasefire agreements and is mandated to protect civilians should a new outbreak of fighting occur. UN troops and police also protect international civilian personnel who administer humanitarian aid and help to oversee compliance with key aspects of the CPA, which includes a referendum on southern independence set for 2011.

South Sudan is clearly on the road to recovery. It is a resource rich territory, and with the security situation much improved foreign investment is starting to flow to the region. Still, there is persistent worry that the government in Khartoum may break the agreement, particularly as the referendum date nears. There are also some outstanding border and wealth sharing disputes, which at times threaten to escalate into broader conflict. But what is really hanging over the head of UNMIS is the conflict in Darfur. Successive UN resolutions have carved out a role for UNMIS in Darfur, but so far the central government refuses to permit significant numbers of blue-helmets from entering Darfur. There is significant concern that pressing Khartoum on this issue may negatively effect the government's compliance with the CPA.

Despite these challenges, the CPA is still holding. But the fragility of the agreement means that peacekeepers will likely remain in south Sudan for the foreseeable future.

Editor's Note: Keeping the Peace will be a month long series of the Posts on Peace campaign. We will provide a snapshot of the history and current challenges facing nearly every peacekeeping mission around the globe. Next up: UNMIS, the 10,000 strong peacekeeping mission in southern Sudan. Enjoy.

In 1991 Haitian military officers deposed the popular and democratically elected president, Jean Bertrand Aristide. Aristide fled to the United States, but his remaining supporters quickly suffered at the hands of the new regime. Massive political violence and general lawlessness soon wracked Haiti. Thousands of Aristide's supporters were slain. And many of those who survived opted to test their luck on rickety fishing boats destined for the United States.

By 1993, the United States Coast Guard had intercepting tens of thousands of these so-called "boat people." Clearly, something had to be done.

With a looming refugee crisis and growing instability in a country only a few hundred miles from Florida, the United States government sought to intervene. In July 1994, the Security Council authorized the deployment of a US-led multinational force to Haiti. 20,000 US marines were soon heading there to facilitate the return of the Aristide government and help restore law and order. This initial US-led deployment was followed by successive UN missions in Haiti. Today, the heir of the initial American-led intervention is MINUSTAH, which was authorized by the Security Council in February 2004.

The Council approved this newest mission when Aristide fled the country amidst an insurrection that threatened to unleash a new round of violence. But this time around, American marines were not at the UN's disposal. Rather, there are some 8,000 uniformed personnel in MINUSTAH, including over 7,000 (mostly Brazilian) troops and over 1,800 police. Their job is tough. While Haiti has demonstrated steady political progress, ruthless gangs still exert de facto control over much of Port-au-Prince's sprawling slums.

On February 7 2006, Haiti held presidential elections that were supported by UN agencies. Rene Preval, a former aid to Aristide, won and asked peacekeepers to help oversee efforts to disarm and reintegrate Haiti's fractious militias and criminal gangs. To that end, MINUSTAH recently undertook its most ambitious mission to date. In February, peacekeepers entered Cite-Soleil, Port au Prince's largest slum, to arrest a shadowy crime boss known only as "Evans." During the crackdown peacekeepers went block-by-block to rescue neighborhoods from the grip of this ruthless mobster and extortionist. The crackdown continues to this day.

Since the deployment, fifteen blue helmets and three police officers have been killed, making Haiti one of the more dangerous peacekeeping missions on the planet. This year, the MINUSTAH will cost member states $489.21 million. According to the United States General Accountability Office, this is a bargain. In 2006, a detailed GAO study compared Haiti's UN mission to a hypothetical American deployment and found the UN mission in Haiti achieves the same objectives while being eight-times less expensive.

The reason for comparison is obvious. Being so close to American shores, instability in Haiti poses a direct threat to the United States. As Secretary of State Condoleezza Rice told then-Secretary General Kofi Annan in late 2004, "There are six thousand Brazilian troops in Haiti. If they weren't, there would be six thousand marines."