Saying they defeated fascists doesn’t imply there are no more fascists left.

I can say I hunted deer, that doesn’t mean there are no more deer left in the wild.

By referring to “fascists” (the people) rather than fascism (the ideology) you narrow your description to more accurately present the scope of your statement. The German Nazi party were fascists. They were defeated. We defeated fascists that day. There are more fascists, but that doesn’t mean we didn’t fight and defeat some number of fascists.