We fought the British. We fought the Mexicans. We fought the Japanese. We fought the Vietnamese. When those battles were over there were still Brits, Mexicans, Japanese, and Vietnamese.
We also fought Confederates and Nazis. Two things that were different about these wars.
One, the death toll. Including all deaths during war, from the American Revolutionary War to the wars in Iraq and Afghanistan (but not counting the deaths of Confederates), about one million American military have died. The number who died fighting Confederates and Nazis? 73% of that.
Two, when those wars were over, Confederates and Nazis had been eradicated. They no longer existed. We dropped atomic bombs on two Japanese cities but Japanese still existed at the end of that war. We took Texas and California from the Mexicans but Mexicans still existed at the end of the Mexican - American War. At the end of WWII there were no more Nazis. At the end of the Civil War there were no more Confederates. Those were the only times in history that Americans didn't just defeat an enemy but eradicated them. This would seem to make you a true American if you stand up against Confederates and Nazis
Until, of course, they started showing up at demonstrations within .... the United States.