Jesus Tap-Dancin' Christ

Here's a better ITWA explanation:

Allies. I mean, with all those nasties trying to off you, having a buddy helping you out really is nice. And, naturally, if he falls, you may too, so you decide to watch his back too.
As for the cleaner fish--WWII saw no bombs or artillery shells fall into the lands of the Swiss. Occaisionally, somebody decided to declare neutrality and, since one front less is that much more in resources to devote to the enemy, they readily acknowledge such neutrality.

What we have here is a clear example of a pair of ITWAs deciding to join forces and eliminate one front and combine arms against another common foe.

DefCom levels on these are most likely at 5.