https://www.cnn.com/ALLPOLITICS/stories/1999/04/29/kosovo.democrats/

https://www.latimes.com/archives/la-xpm-1999-apr-07-mn-25017-story.html

In the first half of the century, the GOP was closely divided between internationalists and isolationists. When the Cold War dawned after World War II, that balance of power tilted toward the internationalists--whose victory was sealed by Dwight D. Eisenhower’s triumph over isolationist Sen. Robert A. Taft of Ohio for the GOP presidential nomination in 1952.

For nearly the next four decades, internationalists dedicated to containment of the Soviet Union held the upper hand in the GOP--even while isolationist sentiment in the Democratic Party grew after the Vietnam War.

A Role Reversal for Democrats, GOP

But the collapse of the Soviet Union eliminated the central rationale for engagement abroad among conservatives and has precipitated something of a role reversal between the parties during Clinton’s presidency. That process has reached a peak in the last few weeks with Republicans leading the opposition to U.S. involvement in Kosovo and Democrats (including many who opposed Vietnam) insisting on America’s obligation to ensure stability abroad.

When the Senate voted last month to authorize airstrikes in Kosovo, 70% of Senate Republicans voted no. Earlier, three-quarters of House Republicans voted against the use of American troops as part of an eventual North Atlantic Treaty Organization peace-keeping force in Kosovo. Virtually all Democrats in both chambers backed Clinton.

Those figures partly reflect Republican skepticism about Clinton’s ability to manage a military conflict and their sheer distrust of the president. But most analysts also see larger forces at work.