At the Democratic presidential debate this weekend, left-wing challenger Bernie Sanders seemed uncharacteristically unsure of himself. In the wake of the horrific Paris attacks, many of CBS News moderator John Dickerson's questions focused on foreign policy, and Sanders outlined a reasonable, indeed rather mainstream, vision of his thinking on the subject. It made for a jarring contrast to his fluent, root-and-branch critique of domestic American politics as a fundamentally corrupt oligarchy.

Hillary Clinton, by contrast, was simultaneously much more sure-footed during Saturday's debate — and also consistently on the defensive. She was confident, and clearly more familiar with the foreign policy terrain, than either of her Democratic competitors. But it was also obvious that she was wary of sounding excessively hawkish before a Democratic electorate sick of war.

So with Clinton mostly concerned with avoiding controversy and protecting her left flank, and Sanders on unfamiliar ground, and Martin O'Malley doing who knows what, nobody articulated a strong, clear foreign policy vision. That's a shame, because a forthrightly left-leaning foreign policy perspective has been sorely missed in American debates for the last generation and more.

President Obama has been two-faced on foreign policy. He has not managed to close Guantanamo. He did not prosecute anyone for flagrantly illegal torture. He has deliberately assassinated at least one and perhaps as many as four American citizens with zero due process and no explanation. The drone war has been massively expanded during his presidency, with enormous collateral damage, including many, many children. American Special Forces operated in some 135 countries last year.

Then again, Obama's record is surely a massive improvement over his immediate predecessor. That's a low bar, as George W. Bush had arguably the worst foreign policy record in all of American history, but it's still true — and doubly relevant as conservatives appear to have learned nothing at all from Bush's ignominious tenure.

And as Matt Yglesias points out, in addition to avoiding any world-historical catastrophes, Obama has also racked up a number of notable diplomatic successes. None of the following were mentioned during the debate:

-A broad multilateral agreement to disarm Iran's nuclear program

-The New Start arms control treaty with Russia

-The historic diplomatic opening to Cuba

-Bilateral agreements on climate change with China and India

-An increase in positive perceptions of the United States in almost every region of the world [Vox]

Quality diplomacy is a major liberal strength. There's a lot more to foreign policy than picking which people are next up to be bombed in the Middle East, and with what expensive ordnance. Obama's quiet, urbane reasonableness (particularly coupled with John Kerry's goofy but effective persistence) makes for a real breath of fresh air. They've got the diplomatic victories and an improved national image to prove it.

Still, Obama has plenty of failings. And they demonstrate the value of all-but-forgotten liberal ideals, perhaps best summed up today by the French slogan of liberty, equality, and fraternity. These have always been tenuous (at best) American values, but they are part of our history.

Obama is not much for this sort of high-minded idealism. For all his relative diplomatic success, he has largely embraced the Bush-Cheney security state when it comes to civil liberties and terrorism. He maintains the value of dragnet surveillance and extralegal drone-bombing with an appalling rate of civilian casualties (and unknown mass psychological trauma from endlessly circling planes). The CIA is still a pack of vicious, lawless incompetents. We're still arming Saudi Arabia for their war in Yemen, which is becoming yet another humanitarian emergency. Chances are good we'll regret this, and soon.

I, for one, would like to see a Democratic candidate stick up for the values of the Bill of Rights, the Declaration of Independence, "The New Colossus," and the Reconstruction Amendments. Someone who would point out that only an abject, un-Christian coward — such as Massachusetts Gov. Charlie Baker, among 18 others — would simply close the borders to refugees (doubly so when all Paris attackers known so far were EU citizens). Someone who would recognize that simply torching one's civil liberties is an extremely stupid way to fight terrorism — but should it come to that, maintaining a free and open society is worth enduring some risk.

Freedom of speech, assembly, and the press; the right to vote; freedom from slavery and police abuse; the right to due process and a trial by jury; these are not just weak liberal pieties to be trodden underfoot at the first sign of terrorism. They are the fundamental ideological underpinning of all Western societies, and Americans forget them at their peril.

Chris Christie says even "3-year-old orphan" refugees are too dangerous to let in. It's lucky Nicholas Winton did not think as Christie and his party do. But the truth is that today, America has seldom been safer from serious danger. Sheltering desperate refugees is not weakness — on the contrary, it indicates a nation that is strong, rich, and confident enough to provide for the hungry stranger. Instead of a politics of terror, let us have a politics of courage.