Ah yes, Canada and Denmark's epic battle for Hans Island.
Hans Island is the smallest of three islands not far from Greenland's coast, and Canada and Denmark have been fighting over it for years.
War ships from both sides patrol the area, and when they encounter each other they...show their flags.
When the soldiers leave the ships they...take the other side's flag down and raise their own.
Sometimes they leave a bottle of whiskey too.
Quite possibly the tamest war ever, yet USA and Sweden have tried their best to make the sides hate each other. USA's media have had stories about Denmark "invading Canadian soil" and Swedish media had a few stories about it as well and later comedians called Danish politicians and pretended to be Canadian politicians.