What can Trump do about Ukraine, Iran, China and crises around the world?

That argument aside, there are certainly some diplomatic opportunities that Mr. Trump could seize, although history and recent ominous warnings suggest that he might relent his opponents and allies with threats of military action if he doesn’t get his way. (See: Iran, Greenland, Panama.)

Here’s a scorecard you can keep handy for the first few months.

In the fog of war, a Ukraine deal is possible

There is little evidence to suggest that Mr. Putin is keen on a deal that would extricate him from a war that has already cost Russia nearly 200,000 dead and more than half a million wounded. But the assumption is that he should be looking for an off-ramp. Since his televised debate with Vice President Kamala Harris, Trump has been promising exactly that — reaching a deal “within 24 hours,” or even getting it done before he takes the oath of office.

Now, not surprisingly, it seems a bit more complicated. His special envoy for Ukraine, Keith Kellogg, an 80-year-old retired general who served on Trump’s first National Security Council, recently told Fox: “Let’s limit it to 100 days” to make sure “the solution is strong and sustainable.” And this war must end so that we can stop the massacre.” Mr. Trump said he would meet with Mr. Putin “soon,” which is notable timing, especially since Mr. Biden has not spoken with the Russian leader in nearly three years.

What could a deal look like? First, most Biden and Trump officials acknowledge, at least privately, that Russia will likely keep its forces in the roughly 20% of Ukraine it now occupies — as part of a truce similar to the one that stalled, but has not ended. The Korean War in 1953. The most difficult part of any agreement is the security agreement. Who can guarantee that Putin will not use the cessation of fighting to rearm, recruit and train new forces, learn from the mistakes of the past three years, and re-invade?

Biden’s national security adviser, Jake Sullivan, says the Biden team has spent the past year “putting the architecture in place” to provide that security. But Volodymyr Zelensky, Ukraine’s president, doubts that this is all just talk. Remembering that no one paid much attention to the 1994 security agreement that Ukraine signed with the United States, Britain and Russia, among others, he says that only NATO membership will prevent Putin from attacking again.