Donald Trump’s abrupt withdrawal of U.S. forces from Syria has drawn widespread scorn from Republicans and Democrats alike, and with good reason: The U.S. has betrayed an ally and ceded influence to a gallery of rogues — Bashar al-Assad, Recep Tayyip Erdogan, Vladimir Putin and Qassim Suleimani, to name a few — in exchange for a hollow talking point about ending endless wars.

But give Trump this: He’s turning a remarkable number of foreign policy liberals and progressives into born-again neoconservatives.

That’s a thought worth pondering as the president pursues a foreign policy that, had it been undertaken by a Democratic administration, would likely have been met with considerable approval on the left. After all, getting America out of fill-in-the-blank — Vietnam, Nicaragua, El Salvador, Iraq, Afghanistan — has for decades been the go-to slogan of progressives.

Why, now, should our retreat from Syria be any different?

If the argument is that the Kurds stood by us, depended on us, and helped us to wage a difficult war, well, so did many others, such as the Montagnards in Vietnam. If the argument is that our retreat from Syria creates the conditions for a humanitarian disaster, one must ask: Where was that humanitarian concern when much of the left was agitating for immediate U.S. withdrawal from Iraq as terrorist and sectarian violence exploded in 2005 and 2006? If the argument is that we are sending a fatal signal of fecklessness to friend and foe alike, why were so many liberals prepared to give Barack Obama a pass when the al-Assad regime violated his chemical red line in 2013?

And if the argument is that we are vacating territories in which terrorists are sure to flourish, why are major Democratic presidential candidates uniformly in favor of withdrawing from Afghanistan, to the guaranteed benefit of the Taliban and their inseparable allies in global jihad?

The real difference is that the current exercise in retreat is being orchestrated by Trump. True, one can quarrel with the speed and manner of the withdrawal, along with the president’s bizarre, inane, and self-aggrandizing defense of the deed. One can also argue that our presence in Syria, unlike our involvements elsewhere, yielded high geopolitical returns at relatively low cost.

Yet the U.S. suffered just 14 fatalities in Afghanistan last year while preventing the Taliban from overrunning the country. Maybe the Democratic contenders will change their minds on that score once they notice that Trump is on their side.

And not just on Afghanistan. Trump’s embrace of policies once more popular on the left than the right seems to have had an extraordinarily clarifying effect regarding the consequences of those policies.

On Russia, Obama attempted a famous “reset” in 2009 to much liberal fanfare, despite the fact that Putin had invaded Georgia just the year before. Trump’s abortive reset with the Kremlin (however suspect its motives) seems to have awakened former reset fans to the belated understanding that the Russians are not our friends.

On North Korea, many liberals loudly assailed Trump for his “fire and fury” rhetoric about Kim Jong-un. Now they mock him, correctly, for his naïveté about the North’s malign intentions.

On Ukraine, the Obama administration’s refusal to supply the country with anti-tank missiles when it was being dismembered by Russia met with consternation from the likes of John McCain, but less-than-vociferous opposition by Democrats. Now the supply of those same weapons has become a vital “insurance policy” against the prospect of renewed Russian aggression.

On economics, the Democratic Party was moving sharply away from its previous embrace of free trade, with both Bernie Sanders and Hillary Clinton opposing the Obama administration’s Trans-Pacific Partnership deal in 2016. Trump withdrew the U.S. from the partnership as one of his first acts of office, and now free trade is back in vogue.

On America’s global role, Obama was lauded by Democrats for pursuing geopolitical “retrenchment” for the sake of “nation-building at home.” Trump has made the identical false promise in the name of “America First.” Only now it’s being condemned as a derogation of America’s global responsibilities.

All of this raises the possibility — faintly — that while Trump steers the American right toward a foreign policy of retreat, appeasement, and non-intervention, liberals might rediscover their Trumanesque faith in the necessity of Pax Americana. The world quickly becomes unsafe in the absence of U.S. power and will. Ceding ground to dictators is destined to work about as well today as it did when it was last tried in the 1930s.

I won’t get my hopes up yet. Trump’s foreign policy ought to be a lesson to all Americans about what a post-American world would look like. So far, the result seems mostly to be a George Costanza exercise in doing the opposite.– Bret L. Stephens has been an Opinion columnist with The New York Times since April 2017.

– Bret L. Stephens has been an Opinion columnist with The New York Times since April 2017.