HOLLYWOOD HAS an almost inexhaustible capacity to irritate politicians, both foreign and domestic. The recent film "300," which tells the story of a few hundred Greeks holding off a massive army of invading Persians in 480 BC — saving Western civilization from death in its cradle — has outraged the government of Iran. The latter-day Persians complain, among other things, that filmmakers portrayed Great King Xerxes as a two-dimensional tyrant. He was, of course, a three-dimensional tyrant, and Iranian President Mahmoud Ahmadinejad seems determined to follow in his footsteps.

Iran is already subject to international sanctions because of its nuclear weapons program. It also is one of the few modern states that continues to use hostage-taking as a tool of statecraft — as it once again proved with the March 23 seizure of 15 British sailors in Iraqi waters. Taking hostages is, of course, a serious violation of international law, but the Iranian government is an old hand at it.

Shortly after the current regime came to power in 1979, U.S. diplomats in Tehran were unlawfully seized and held as prisoners for 444 days. The pretext that the Americans were held by Iranian "students" acting without government sanction was as risible in 1979 as are Tehran's current claims that the British sailors violated Iranian territorial waters. Ever-watchful global positioning satellites show they did not.

No matter where the Iranian capture took place, Tehran's British detainees are entitled to all of the rights and privileges of prisoners of war under the Geneva Convention. They are the regular service members of a sovereign state. They were on duty, in uniform and following lawful orders when they were taken captive in an unprovoked act of aggression.

The Geneva Convention, which binds Iran, requires that the captives be treated honorably and humanely. POWs "must at all times be protected, particularly against acts of violence or intimidation and against insults and public curiosity." This includes parading them before television cameras and using them as propaganda tools, as has already been done. They are entitled to contact with the International Committee of the Red Cross, and they may not be used as hostages.

Moreover, once the armed conflict that brought the Geneva Convention into play — Iran's capture of the British force operating in Iraqi waters — has ended, they must be released at once. Unless Iran now considers itself to be engaged in active hostilities against Britain — and potentially, with Britain's allies such as the United States — the sailors must be repatriated. POWs cannot be held beyond the close of active hostilities. That is the law.

It is doubtful whether Iran will comply. It has reneged on its promise to free the one female British POW because of Britain's threatened freeze on bilateral diplomatic relations. This makes clear its intentions to use innocent men and women as bargaining chips to obtain other advantages. We can expect efforts by Tehran to exchange the Brits for the five Iranian infiltrators recently captured in Iraq by U.S. forces, or for the former Iranian deputy defense minister, Ali Reza Asghari, who is believed to have defected to the West in February.

The international community's failure to show immediate outrage at Iran's action is deafening. Ancient legal principles governing how states make war are on the line. Compliance with the laws of war is most important at the time of actual conflict. These principles are already, unfortunately, under assault by terrorist organizations like Al Qaeda. Permitting a United Nations member state that is also a regional power like Iran to violate these norms repeatedly and with impunity would have grave humanitarian consequences for the future.

U.N. Secretary-General Ban Ki-moon, at least, understands the stakes. He has already opened talks with Iran. But the U.N. Security Council adopted a weak statement Thursday expressing only "grave concern" at the capture of the sailors. Britain was unable to win a stronger council statement to "deplore" the Iranian action, mainly because of Russian objections to a provision that stated that the British were in Iraqi, not Iranian, waters.

If the Security Council cannot even "deplore" the unlawful detention of prisoners of war, let alone take more forceful action when a sovereign state chooses to act — openly and unapologetically — like a transnational terrorist organization, then it would better have remained deadlocked and silent. It is worthless as a guarantor of international peace and stability. The Iranian government has chosen to act as an international pariah, and it is time it is treated as such.