Never in the past few decades at least has an American president engaged in such an angry, scathing attack on a visiting foreign leader in the Oval Office.

Emboldened by President Donald Trump’s suspension of military aid and intelligence to Ukraine, Russian forces have stepped up the pace of air attacks and redoubled efforts to take back captured territory in the Kursk region in what appears to be an attempt to solidify its battlefield position ahead of a forced surrender

The public blowup could propel President Vladimir V. Putin of Russia to escalate the fight in Ukraine instead of agreeing to peace.