Makes sense, considering the Belgians invented Frites. The American soldiers came to fight in Belgium during WWII. Not only was French used as the Belgian army's official language at that time, but the French and Belgian uniforms were very similar. So, the poor dumb Americans mistakenly assumed they had yet to cross the border from France to Belgium. That's how Frites/chips got the name "French Fries".
Honestly, I don't care what they're called, since they're going into my mouth either way.