New developments Tuesday reinforced the idea that President Donald Trump has significantly shifted his view of the Ukraine war.

MICHAEL KIMMAGE is Professor of History at the Catholic University of America. He is the author of Collisions: The Origins of the War in Ukraine and the New Global Instability.

On Monday, Trump said that Russia's failure to reach a negotiated settlement with Ukraine within 50 days would lead to his administration imposing a 100% tariff rate on Russian imports as well as what he called "secondary tariffs" on countries that have continued to do business with Moscow.

That included a Monday joint statement from Republican Sen. Lindsey Graham and Democratic Sen. Richard Blumenthal calling Trump’s threat of ramped-up economic penalties if Russia doesn’t cut a peace deal in next 50 days “a real executive hammer to drive the parties to the negotiating table.”

“Putin will not negotiate as a loser,” one of his longtime associates tells TIME by phone from Moscow. “He knows that winners don’t get punished, and if he wins, all of this” — the sanctions, the tariffs — “will go away.”

Pres. Trump has denied reports that he asked Pres. Zelenskyy to strike deeper into Russia, but said he is increasingly "disappointed" with Putin's ongoing heavy bombing of Ukraine.

President Vladimir Putin intends to keep fighting in Ukraine until the West engages on his terms for peace, unfazed by Donald Trump's threats of tougher sanctions, and his territorial demands may widen as Russian forces advance,

President Donald Trump issues Russian President Vladimir Putin a 50-day deadline to end Ukraine war or face 100% tariffs, prompting skepticism from the EU's chief diplomat and Kyiv's mayor over 50-day timeframe.

Trump said he would end the war in Ukraine within his first 24 hours in office. His patience with Russia's Putin now appears to be wearing thin.

Russian President Vladimir Putin has sacrificed an estimated 1 million of his soldiers, killed and wounded, in a three-year campaign to crush Ukraine.

President Donald Trump announced this week that the U.S. will send Patriot air-defense missiles to Ukraine and threatened new tariffs on Russia. Will Vladimir Putin back down? What should Trump's next move be? And what does the future hold for Ukraine? Newsweek contributors Daniel R. DePetris and Dan Perry debate: