Trump says he could have prevented the Russian Invasion by agreeing to letting Russia keep part of U

What really happened is he delayed any lead time that the US and NATO would have had to negotiate a solution to a problem with Putin.  Wasted 4 years or more.  Remember the “perfect call” with Ukraine President?  I am sure that Putin though he had a buddy in Trump.  Our country knew that this invasion was in the making, but Trump effectively failed to address the situation.  Now he said he could have stopped it????