Not really. Republicans were accused of "isolationism" by Wilsonian Democrats in the first half of the century.
Both political parties have had both intervenionist and anti-interventionist wings throughout their history. Among Democrats, you had both pacifists and Wilsonian activists, and among Republicans, you have/had both Old Right anti-interventionists and war hawks.
The only question is which faction of the party is dominant, when, and for what reason. Unfortunately, usually the way it works is this: if a Democratic President wants to get involved in a war, the Republicans allow the libertarian, anti-interventionist wing to speak because of partisan politics, while Democrats keep their pacifists quiet. Conversely, if a Republican administration starts a war, liberal pacifists become less marginalized by their party elites, not out of principle, but because of party politics.
hummingbird