Vladimir Putin started it. Joe Biden didn’t stop it. But, no matter his efforts to the contrary, this is the week in which Russia’s invasion of Ukraine becomes US President Donald Trump’s war.

Previous Trump promises, threats and cajoling have failed to yield results., and the stubborn diplomatic stalemate will be hard to clear away. Meanwhile, Ukraine is losing more territory on the front line, although there is no sign of a looming collapse of its defenses.

President Trump has given an ultimatum to President Vladimir V. Putin of Russia to end the war in Ukraine or face U.S. sanctions.