Is it possible to fabricate a casus belli without using the focus tree?

[Hobo Humpin Slobo]

(in this game as well) ... or are you limited to the options provided there?

[Barry White]

Yes. The claims given in the foci only make it faster and free to fabricate claims.

[mbpoblet]

It costs political power and if you're democratic you need the world tension to be above a certain threshold, if I'm not mistaken (and if you're fascist, or possibly communist, whoever you're fabricating on will probably get guaranteed by the UK and or France, if they're democratic, thus starting WWII if you attack them), but yeah, other than that it's a diplomatic option; as Barry said, though, the focus tree is probably the easiest and safest way, if you want a chance of delaying the start of the war (and, as Germany, for instance, you can even get some territories like Austria, the Sudetenland, Memel, Checkoslovakia, and, if you're lucky and Poland is feeling generous, even Danzig, without javing to fire a single shot or triggering the war, which wouldn't be an option with regular fabricated claims).