When it comes to Syria, it is strange how one particular group, which was outspoken during and after the US invasion of Iraq, has been so quiet. They are the people who pointed out that the Iraqi intervention in 2003 was illegitimate because it was not sanctioned by the UN Security Council. Yet today, as carnage continues in Syria, no one has mentioned that a deadlocked Security Council has only meant endless suffering for Syrians entitled to UN action.
If UN approval is the benchmark of legitimacy for foreign military intervention, then what about a lack of approval? Some 60,000 people are said to have died in Syria, and yet the international community has been unable to alleviate this ghastly state of affairs. Syrians are being wantonly killed, and one doubts whether they really care if outside powers that would assist them first gain UN consent.
This mood pushes the debate over Syria on to a different plane. Accepting that there are situations short of a UN vote where powers can take military measures in a country, let's say on humanitarian grounds, undermines the belief that Security Council endorsement is a necessity. If the suffering of a population is enough to lead to action by states, then it opens the door to intervention on grounds that are well short of those presently required.
The suffering in Syria cries for more than the lethargic international reaction. Bashar Al Assad's regime has gunned down unarmed civilians demonstrating peacefully. It has bombarded neighbourhoods with artillery and aircraft. And it has engaged in collective punishment of districts hostile to central authority. It has also kidnapped and tortured thousands of people, many of whom have disappeared. In short, its repression has been repulsive enough to merit outside involvement against regime forces.
And yet we must remember that in Washington these days, one is unlikely to find any appreciation for this position. President Barack Obama was a staunch critic of the Bush administration's war in Iraq, and is not likely to agree that cruelty on its own warrants America's entry into a war on behalf of a foreign population. Not only does Mr Obama want to draw down forces in the Middle East, a position supported by many at home, he does not want to take a position that might legitimise his predecessor's decision to sent troops to Iraq.
Yet the president did favour armed action in Libya, and explained it as being necessary to save lives. As Mr Obama told an audience at the National Defence University in March 2011: "[Muammar] Qaddafi declared that he would show 'no mercy' to his own people. He compared them to rats, and threatened to go door-to-door to inflict punishment ... We knew that if we waited one more day Benghazi … could suffer a massacre that would have reverberated across the region and stained the conscience of the world."
How strange to see the president reaching for a human-rights argument in that context, something he now refuses to do in Syria. Mr Obama has set just one red line there: the employment by regime forces of chemical weapons. However, the standard is so high that the Syrian army can kill at will while avoiding any resort to such weapons. Is such a tripwire for action useful, so that it is apparent that Mr Obama is simply dancing around taking a decision?
Mr Obama has often made the case that the United States can no longer afford the commitments of the past. That's perhaps true, but in the present context does it really serve Washington well to appear so half-hearted? Syria is no secondary conflict. What happens there will affect vital US interests, above all the containment of Iranian influence in the Levant. Only days ago, an Iranian official close to Ayatollah Ali Khamenei declared that Mr Al Assad's removal was a red line for Tehran. Mr Obama offered no riposte, although Mr Al Assad's exit will greatly enhance American aims in the Middle East.
In other words, can America be effective if its refusal to go to war is always viewed as a default position? No one is suggesting that Mr Obama dispatch troops at every hint of a threat. America no longer has the financial means to maintain the military posture it did during the years of President George W Bush. But the solution is not to make it clear that military action has been taken off the table.
More important, can America anchor the international system if the worst abuses against international principles go unpunished, largely because Washington is so aloof? It's not enough to support others in such endeavours. France won't replace the United States, even if the French have shown nerve in recent years. France grasped the implications of the Syrian conflict early on, and while its ability to act is limited, it has done more for Syria's opposition than Mr Obama.
International law is not there to validate American inaction. That the UN has been deadlocked over Syria takes us back to the Cold War years and only discredits international collaboration, Mr Obama's purported ideal. If this is acceptable for the Obama administration, for whom stalemate offers an excuse not to act, then it tells us something about American lassitude that is worrisome for the future.
Michael Young is opinion editor of The Daily Star newspaper in Beirut
On Twitter: @BeirutCalling.