Declaring this week that defending Ukraine against Russia’s invasion was not a vital interest for the United States, Gov. Ron DeSantis of Florida cemented a Republican shift away from hawkish foreign policy that has played out over the past decade and accelerated with Donald J. Trump’s political rise.

Mr. Trump and Mr. DeSantis — whose combined support makes up more than 75 percent of Republican primary voters in the nascent 2024 presidential contest — are now largely aligned on Ukraine, signaling a sharp break from the interventionist approach that drove former President George W. Bush’s invasions of Iraq and Afghanistan.

Republican foreign policy hawks recoiled at Mr. DeSantis’s statement on “Tucker Carlson Tonight” on Fox News on Monday night, in which the governor deviated from the position held by most of the Republican establishment on Capitol Hill, including Senator Mitch McConnell of Kentucky, the minority leader. Mr. McConnell and other top congressional Republicans have framed the invasion by President Vladimir V. Putin of Russia as a fight to defend the post-World War II international security framework.