A letter to the editor of the New York Times Book Review says it all. It mentions the situation in Syria and says, “The crisis continues.” The “crisis,” you should know, is not the continuing slaughter of civilians nor the river of miserable refugees spilling over the borders but rather a “crisis of masculinity,” which accounts for why some men have gone dashingly and idiotically off to war in the past — and now want to intervene in the Syrian one.

I cite the letter because its author is Norman Birnbaum, a quite distinguished emeritus professor at Georgetown University. In tone and approach, it is very much like a long article in the New York Review of Books by David Bromwich, a professor of English at Yale and yet another prominent liberal. He, too, chides us alleged war-lovers, reminding us of Iraq, where some of us were wrong (guilty) and some duplicitous (not guilty), and offers instruction on the difficulties and complexities of intervention — Shiites, Sunnis, Alawites and all the rest, a veritable casting call for “Lawrence of Arabia.”

Unmentioned is that those difficulties have been compounded by the furious inaction of the Obama administration. The president has called on Bashar al-Assad to go — and predicted he would — but here he remains, more than two years into the war and more than 80,000 dead along the way. The Syrian dictator may well win this thing. He now has the fresh troops of Hezbollah and, possibly soon, Russian S-300 antiaircraft missiles, which could well make imposing a no-fly zone a non-starter.

What perplexes me is that a good deal of this patronizing criticism of we interveners comes from the left. The argument is that Syria would be Iraq all over again. This is tendentious. The whole idea of intervening early — it may already be too late — was not to impose some U.S.-friendly regime but merely to stop the killing and avoid an immense humanitarian calamity. Early on, this was possible. The proposal was to arm the moderate rebels, impose a no-fly zone and throw the weight of the United States behind the effort to topple Assad. “Boots on the ground” — the schoolyard taunt to an argument never made — was never contemplated. The business plan was for the United States to venture little but gain much — leveraging, I think it’s called.

Syria was never going to be the Iraq war. It was going to be a humanitarian intervention, an attempt to stop the killing, end the misery — use U.S. power to do good. This was not colonialism or neocolonialism or imposing a repellent Western regime on the always virtuous East. All we wanted — all I wanted — was to end the killing. Only the United States had the wherewithal to do this.

In 1933, the Oxford Union debating society approved a resolution saying that it would not fight for its king and country.The resolution was a fair approximation of the British mood at the time, especially among the upper classes. It was a perfectly understandable, yet unforgivable, reaction to the horrendous slaughter of World War I, carnage so great and unprecedented that victory seemed indistinguishable from defeat. With a population of around 40 million, Britain lost some 900,000 men. It won, aside from victory, virtually nothing. The consequence was a pernicious pacifism, which cheered Hitler and infuriated Churchill.

Something like that is happening now. The reaction to the Iraq war has produced a there-they-go-again-syndrome, so that a proposed humanitarian intervention is sneeringly dismissed as if the rallying cry is “on to Baghdad.” More depressing still is the total lack of concern for the misery of Syrians. Rarely do any of these anti-intervention pieces cry bloody murder at the killing that continues apace in Syria. Liberals, once characterized as bleeding hearts, seem now to have none at all. They agonize over the slippery slope, not the horror of mounting civilian deaths.

I have always recognized the difficulties of any intervention in Syria and the hideous ethnic complexities of the place. And I recognize, too, that no threat like Hitler is out there. But there will be consequences nonetheless. The United States has impeccably conducted itself as a blowhard. The president demanded that Assad resign; he warned direly of red lines. But who believes it? Once again Barack Obama is doing his Prince of Denmark number. We have squandered our leadership — actual and moral — and done nothing to save lives. We might have contained a war that is spreading daily. We could at least have tried. It’s been a shameful performance.

Read more from Richard Cohen’s archive.

Read more on this topic:

Richard Cohen: Obama’s loss for words on Syria

Eugene Robinson: Stay out of Syria

Anne-Marie Slaughter: Obama should remember Rwanda

The Post’s View: No muddling this ‘red line’

Jackson Diehl: Watching Syria’s descent