This year is shaping up to be a nail-biter for Ukraine. 

After a year of significant gains for Russia, looming large is the presidency of Donald Trump, who has pledged to end the war in “a single day” — even if he has indicated that he is in part sympathetic to Moscow’s arguments and has remained skeptical of promising open-ended military aid to Kyiv.

Some experts believe that, for this reason, it’s likely that Ukraine, and Europe, will need to prepare for a prolonged war.

“Trump,…