The enemy of my enemy is my friend. The old proverb has resulted in such unlikely alliances as the United States and the Soviet Union vs Germany, or the former aligned with China (yet-to-be-communist) against Japan. This is the nature of international relations. It’s sometimes also the nature of business, when two or more rivals put down their gloves to turn their sights on a bigger fish.
This is what’s transpiring in Samsung’s ongoing patent feud with Apple. Though they are competitors in the Android market, HTC, LG, and Samsung all have a united interest in fighting Apple on intellectual property. Google itself is also deep in the mix, having been in Samsung’s corner for a bit longer already.