U.S. President Barack Obama is busy trying to cement his legacy, which is in danger of being reversed and undone by his successor, Donald J. Trump, about whom I have nothing much good to say.

Obama has finally, belatedly, possibly, woken up to the threat that Russia poses to the civilized world. He’s issued new sanctions (though, as usual, tepid) for the Kremlin’s brazen interference in the recent presidential election won by Hillary Clinton in the popular vote but by Trump in the only vote that matters in America — the Electoral College vote.

He needs to go the next step and hop on Air Force One and get to Kyiv in the waning days of his presidency. There’s still time. He can get here in eight hours by air. Very little preparation or planning is needed. If the weather allows, call for a rally on St. Sofia Square — it will be filled in minutes. Or go to Olympic Stadium or, if indoors, October Palace and have your speech live streamed everywhere. Or, better yet, don’t let U.S. Sen. John McCain, your 2008 opponent, outdo you. He spent New Year’s Eve near the war front in Mariupol. You can do the same for Orthodox New Year on Saturday, Jan. 14.

Tell Ukrainians that, while you’re sorry you were almost the first president since Ronald Reagan not to visit Ukraine (historical note: Richard Nixon and Franklin D. Roosevelt are also among ex-U.S. presidents who have visited Ukraine), you have recently come to agree with your 2012 opponent Mitt Romney that Russia represents the greatest geopolitical threat today. You’d be right.

Tell Ukrainians that you have dropped your opposition to supplying lethal weapons and that, in your future role as ex-president, you will support Ukraine’s aspirations for NATO and European Union membership as well as visa-free travel to America.

Tell Ukrainians that while you support them, you will not support their corrupt leadership and will insist on complete transparency for every single dollar given or lent to the nation.

Tell Ukrainians that you understand that their fight is America’s fight — for democracy and national sovereignty against the tyranny of a foreign imperialistic power.

Tell Ukrainians that the United States and Great Britain owe greater security assurances under the 1994 Budapest Memorandum under which Ukraine surrendered its nuclear arsenal.

Tell Ukrainians that America should have done more to warn them and prevent Russia’s military invasion and takeover of the Crimean peninsula.

Whatever you tell them, just come here please. It would be a wonderful way to end your presidency — delivering a presidential message of hope in a nation that did more than any other to inspire the world’s aspirations for democratic change and victory over tyranny during your time in office.