Despite rising skepticism of American involvement in Ukraine, President Biden has offered up a clear signal of his continued resolve to escalate the conflict with another $400 million in military aid. 

The aid package adds to tens of billions in weaponry that Biden has poured into the conflict zone since the war began more than a year ago.

Russia had anticipated Biden's latest aid package with a warning that sending more weapons would "prolong the conflict and have sad consequences for the Ukrainian people."

The White House has said that Vladimir Putin has the capability to end the war by withdrawing his forces, but Putin has shown no sign of doing that.

Biden escalates?

Putin sent a warning shot last month by formally suspending the New START treaty, which was the last nuclear arms agreement between the U.S. and Russia.

Putin doesn't have much room to de-escalate, having framed the war as a struggle for Russia's survival that was provoked by the United States and NATO.

"They intend to transform a local conflict into a phase of global confrontation," Putin said. "This is exactly how we understand it all and we will react accordingly, because in this case we are talking about the existence of our country."

Biden traveled to Europe last month to rally the West against Russia in what he has characterized as a morally charged battle for Western "democracy." He denied Putin's claims that the West's real goal in Ukraine is to bring about regime change in Rusia.

"The United States and the nations of Europe do not seek to control or destroy Russia," Biden said in Poland.

"As long as it takes"

Biden has mostly appeared to brush aside concerns the war could escalate into a world war, pledging to support Ukraine for "as long as it takes" even as sentiment shifts at home in the U.S.

A year into the conflict less than half of Americans say they support sending Ukraine weapons. Skepticism has risen particularly among "America First" Republicans, who say Biden's open-ended commitment to Ukraine has come at the expense of American interests.

Pentagon officials told skeptical Republicans last week that there is "no evidence" that U.S. materiel sent to Ukraine, a country notorious for government corruption, has entered the black market.

The latest aid package included more ammunition for HIMARS precision rocket systems.

While Biden has been mostly generous about aiding Ukraine at taxpayer expense, he has notably refused Ukrainian president Volodymyr Zelensky's demands for F-16s fighter jets, at least for now.