Some of them involve Ukraine. Trump and his national security adviser have both hinted that recognition of the Russian occupation of Crimea is on the table; Trump even repeats Russian propaganda about Crimea’s ethnicity and politics. Another was laid out in The Post by David Ignatius a few days ago: Trump may be planning to cede Syria to Putin, abandon U.S. allies on the ground and allow Russia’s client, the dictator, Bashar al-Assad, to reestablish control across the country, inflicting massive civilian casualties along the way.

In neither case is it clear what the United States would get in exchange for these major concessions. One version says Putin would promise to withdraw the Russian troops whose presence he denies from eastern Ukraine. Another says Putin would promise, somehow, to contain Iran, a country with which, in Syria, he is allied. Talk of this latter deal dates to the earliest days of the administration, back when Jared Kushner, all those months ago, sought a secret channel of communication with the Russian government.

But all these deals, just like the original Yalta agreement, have at their heart a fatal flaw: They rely on promises from a Russian leader who has never, in Syria, Ukraine or anywhere else, kept his word.