What decides who will join wars against me?

[fullerfamily]

It seems like everyone else is rolling through conquest except me.

My most recent failures are with Egypt. I can't conquer/puppet/etc any of the OPMs in Arabia without the major nations joining the adversary. If Ottomans attack me, and I defend with war goals to take territory they often get a major on their side as well. I am struggling to expand.

Relations with those countries appears to do nothing. What decides who will join wars against me?

[Toblm]

In no particular order:
Relations, alliances, trade partnerships, how occupied other powers are, bribes, regional interests, obligations, infamy, national principle/attitudes (and likely other things that dont come to mind atm) all effect who will or will not join wars.

As Egypt making good friends with Russia and/or Austria will help you out against the Ottomans. UK can be a decent choice against the Turks but I've found they like to expand in Arabia themselves, so not the best long term friend.

[teron]

You also can do a more indirect approach of the following:
- For example, if Russia would get involved in a diplo play against you attacking some country. Wait for them to start a diplo play (or be targeted) join their side, then start yours. Since you can't be allies and enemies in different wars at the same time
- If the country you want to attack has an ally in a different area of the world that has disinterested GPs or no GPs. Attack that ally, then bring war goals against the country you really want. Since people involved in the diplo play will be the ones with interest in that area/allies/defensive pacts

Take advantage of GPs when they have rebellions is nice. Did that in my current game to Austria by puppeting countries that they were allies/defensive pacts with during their major civil wars. Since Austria would instantly abandon due to being busy with their civil war.

Also look for areas where the GPs are not interested in, I had a game where Cape colony broke free and the only European country interested in the Area was Portugal. Thus I could go on a puppeting and later annexing my puppets without having to worry about having to really fight for the land.

[fullerfamily]

Thanks. I was able to handle the Ottomans and expand elsewhere.