Which way will Samantha Power jump?

As the Obama administration's policy to end the five-way civil war in Syria – what Secretary of State John Kerry this week called the "greatest humanitarian catastrophe since World War II" – has repeatedly unraveled, no one has likely been more frustrated than the United States ambassador to the United Nations.  Samantha Power has reason to be.  Humanitarian intervention is her issue.

Before entering government, Samantha Power was one of the architects of the so-called "R2P" initiative.  That's the idea, adopted at the 2005 World Summit to prevent genocide and other war crimes, that the U.N. and the major powers have a "responsibility to protect" civilians under the Genocide Convention and other treaties when a country's government turns homicidal towards its own people. Its proponents call it "a new international security and human rights norm."

Its detractors call R2P malarkey and its proponents, like Samantha Power, members of the “cruise missile left.”  Ambassador Power rejects both labels.

In 2002, Power, a former war correspondent who covered the wars following the breakup of Yugoslavia, won the Pulitzer Prize for her scholarly work, A Problem from Hell: America and the Age of Genocide.  In it, she chronicled the history of American indifference to genocide throughout the 20th century, beginning with the Armenian genocide during WWI and on to the Clinton administration's failures in Rwanda and Bosnia.  It also noted how such U.S. humanitarian interventions such as Lebanon in 1983 and Somalia in 1992-93 went tragically wrong.

It was those two episodes that first made "nation-building" – something which America had done with notable success in post-war Germany and Japan – a dirty word.  The bitter U.S. experiences in Iraq and Afghanistan have only reinforced it.

The Obama years have not been kind to R2P proponents.  Darfur and Syria have become nightmares.  And America's humanitarian intervention in Libya to oust Gaddafi went tragically wrong, as did the Arab Spring in Egypt.  The Green Revolution in Iran was crushed, and the U.S. did nothing.  The same story played out in Bahrain and Yemen.  Dexter Filkins is reporting in the current New Yorker that the next humanitarian catastrophe will occur in the besieged Iraqi city of Mosul.

Advocates of R2P like Power have, quite literally, no successes to point to on Mr. Obama's watch.

Now comes this week's Russian bombing of the U.N. aid convoy in Syria to challenge the very credibility of American power in the Middle East.  It was, of course, a war crime.  But the issue is whether the Russian bombing will also prove to be, in Talleyrand's phrase, "worse than a crime, ... a mistake."

What will President Obama do?  Probably nothing.

And that will present Samantha Power with an acute moral dilemma.  Because if the Obama administration again refuses to act decisively in Syria, R2P is dead.

In A Problem from Hell, Power was eloquent in her condemnation of the Clinton administration's refusals to intervene in Rwanda and Bosnia.  And she especially praised the young Foreign Service officers who resigned over President Clinton's indifference toward Serbian genocide and war crimes.

So: what will Samantha Power do?

Samantha Power has a legacy to think about, too.