In addition to a Japanese cargo ship, they have seized possibly their biggest prize since the Ukrainian ship full of tanks -- a Saudi oil tanker transporting over a quarter of the country's daily oil production.

Elizabeth Dickinson points out that the most recent hijackings took place "under the watch" of dozens of international warships dispatched to protect shipping lanes in the Gulf of Aden. This is true, but patrolling the waters off Somalia is not as exactly the same as standing guard over a bank vault; the ships' "watch" would have to extend for quite a few nautical miles to be able to capture every incident of piracy.

Opinio Juris' Kenneth Anderson suggests that incoming Obama administration use the case of piracy "to demonstrate its approach to use of force, multilateralism, and international law." He envisions a rather muscular -- and cunning -- response.

I had a conversation with a US Navy officer, not a lawyer, but someone with operational duties, who suggested that the best military course of action would be to equip some number of civilian vessels as decoys - heavily armed and carrying marines. The best thing, he said, would be for Somali pirates to attack, and then be aggressively counterattacked, in a battle, not the serving of an arrest warrant - sink their vessel and kill as many pirates as possible. It would send a message to pirates that they could not know which apparently civilian vessels might instead instead counterattack.

To "kill as many pirates as possible" seems a little wanton, but I do agree with Anderson that the outbreak of piracy presents an opportunity for the United States to recommit to international accords like the law of the sea, and possibly even the ICC.

Clearly, it will take some sort of aggressive response -- coupled with peaceful efforts on Somalia's mainland, of course -- to deter pirates from further increasing their lucrative banditry. Across the continent, Nigerian militants are already starting to emulate the Somali swashbucklers.

UPDATE: The pirates attacking the tanker were indeed quite a few nautical miles off the coast. And if it had held a certain type of natural gas, it could have had the potential of causing "50 Hiroshimas." Gulp.