So I'm trudging along happily in my Spain campaign, with the usual conficuration (New Spain protectorate, France, Bavaria allies). At this stage I had gotten into alliances with the Knights, Italian States, and had taken out Savoy and Genoa.

And then this happens: Poland Lithuania with its own block of allies (Austria - who I was already at war with: With Venice covering one flank, and France the other, they didn't bother me much...; Denmark, and a few minors) declared war on the Knights!!! None of them had even remote access to the Mediterranean, except Austria, but they didn't have a navy.

So as I was at war with UP at the time, I had refused to help as I was already stretched very thin and needed no danish ships raiding my trade.

So, several turns later, P-L DoW New Spain. What?! They had no provinces or access to the americas, any of the P-L coalition countries. I defended my protectorate, but P-L's allies refused to help them out. Even more amusingly, until I entered the war our relations were "Friendly".

What is going on? Am I missing some game mechanic that's obvious to everyone else?