I have an article in the Globe and Mail today gaming out some scenarios in which a Gaza ceasefire resolution may make its way through the Security Council. When that time comes–and it almost certainly will — the USA will have some tough choices to make. Events on the ground are moving swiftly in Gaza, as Israel and Hamas approach a tentative ceasefire. So too is diplomacy at the United Nations, where the newest flareup of conflict in Gaza is exposing some old rivalries and reversing the old relationship between major powers. The story begins in March 2011, as violence in Syria sharply escalated. For the next 20 months, Russia played the spoiler to American-led attempts to condemn Syrian President Bashar al Assad at the UN Security Council. Russia has historic and military ties to Syrian president Bashar al-Assad, so it has been reluctant to go along with the rest of the Council — and most of the rest of the world — in pressuring Mr. Assad to end the war or give up power. Russia has cast three Security Council vetoes (with China) preventing any sort of punitive measures aimed at Mr. Assad, drawing condemnation from the United States. And now the Gaza flare-up gives Moscow the opportunity to return the favour and force the United States to cast an embarrassing veto for an unpopular cause. Moscow seems to be relishing the opportunity to reverse roles. Read on.