Now is Trump’s chance to stand up to Putin — what will his legacy be?

It is legacy-building time for Donald Trump.

The former president and president-elect has already entered the history books as only the second American to have won the presidency, lost reelection, then get elected again for a nonconsecutive second term. But Trump’s ultimate legacy will prove to be a lot more consequential on national security and foreign policy — for better or worse.

Four major conflicts are either raging or brewing thanks to the anti-U.S. cabal of Russia, China, Iran and North Korea. America’s adversaries will not wait until Trump’s administration is settled in before they begin acting; one or more of them may even decide the opportune time to make their next move is right now, during the two-month interregnum while the Biden administration is disintegrating and the Trump team is still forming and consolidating.

Even if they decide to defer new action until Trump takes office to see what deals or concessions he may offer, the clock is already running on a tight deadline Trump set for himself: settlement of the war in Ukraine.

Several times during his campaign, he pledged to resolve the conflict “within 24 hours.” Trump later doubled down on what already seemed to many an impossible boast by asserting that he would accomplish the feat even before officially taking office on Jan. 20.

All he would have to do, he claimed, was to talk with Vladimir Putin, with whom he has a mutually respectful personal relationship notwithstanding Putin’s record as a war criminal, and with Ukraine’s president, Volodymyr Zelensky, whom he has publicly blamed for provoking Putin’s aggression.

The only way Trump could end the war, it was clear, was to compel Zelensky to endure a partition of his country by accepting permanent Russian occupation of Crimea and/or Eastern Ukraine, and for Putin to accept that he would get no more of Ukraine’s territory. So far, neither leader has expressed interest in the kind of deal Trump is contemplating.

Nevertheless, the Trump team is seeking to make it happen. According to still-sketchy reports, Trump’s plan envisions a quick ceasefire, Ukraine committing not to pursue NATO membership for a period of 20 years, and the West’s continued flow of weapons for Ukraine’s self-defense.

Sure enough, there would be significant territorial concessions on both sides — virtually all of it involving Ukrainian territory, except for a sliver of Russian land in Kursk recently occupied by Ukraine.

In the effort to pressure Ukraine to make concessions for peace, a potentially disturbing development occurred over the weekend. Trump reportedly took a call from Zelensky when, coincidentally, Elon Musk entered the room and Trump gave him the phone. They discussed Musk’s Starlink communications system, which is critical to Ukraine’s wartime operations.

Early in the war, Musk cut off the service and demanded payment, restoring service only when the Pentagon came up with the money for the billionaire. Musk could easily use the Starlink service as further leverage to compel Ukraine’s submission to the Trump settlement if the president-elect chooses to achieve his ill-considered promise in that manner.

Further insight into Trump’s coercive foreign policy thinking came last week when a former aide dismissed any idea that a return of Crimea to Ukraine was included in Trump’s settlement proposal. Bryan Lanza told BBC that the incoming Trump administration would expect Ukraine to have a "realistic vision for peace."

"If President Zelensky comes to the table and says, we can only have peace if we have Crimea, he shows to us that he's not serious. Crimea is gone,” said Lanza. The priority for the U.S. would be "peace and to stop the killing."

The comments suggested a Neville Chamberlain-like posture of appeasement that would attain “peace at any price” and “peace in our time” at the cost of long-time European stability and international order.

Fortunately, as soon as that report surfaced, Team Trump issued a statement that the former aide’s remarks did not reflect the president-elect’s views. “He does not work for President Trump and does not speak for him."

There is still hope that the incoming president will not validate the Obama-Biden administration’s acquiescence to Putin’s original seizure of Crimea.

Trump has a historic opportunity to create a positive legacy of peace through strength more in line with that of Winston Churchill and Ronald Reagan, by standing with Ukraine and putting an end to a weakened Putin’s aggressive rampage.

Xi Jinping, Kim Jong-Un, and Iran’s supreme leader will take notice of the new American sheriff in town. They, together with Putin, should be made to fear the prospect of regime change if they don’t change their hostile and threatening behavior.

Joseph Bosco served as China country director for the secretary of Defense from 2005 to 2006 and as Asia-Pacific director of humanitarian assistance and disaster relief from 2009 to 2010. He is a nonresident fellow at the Institute for Corean-American Studies, a member of the advisory board of the Global Taiwan Institute and member of the advisory board of The Vandenberg Coalition.