It seems to me that interfering in a foreign election should be understood to be grounds for war.
Yes, and the EU, due to this fragmentation, seems to be a fertile playground for all this unacceptable interference by foreign powers.
Actually, no. The decentralization of power means that it takes a lot more effort to subvert each country individually, rather than propping up a few candidates for the entire region like they do in the US.

That’s true but that fragmentation is also what limits the propagation of fractures. You can see it like sandboxing.

A deal with foreign intelligence is a dead with the devil that comes with a lifetime of subservience. And subservience to foreign powers is a greater evil than yo usual internal corruption. At least the locally corrupt in a democracy have some interest in things going somewhat well in their country. The foreign actors only care about theirs.

No because any attempt at interference would in that case trigger article 5 of NATO.

> interfering in a foreign election should be understood to be grounds for war

Requires a rigorous definition of interference.

The allegations here—trying to catch politicians on tape being sleazy and then releasing them-doesn’t seem to rise to the level of calling for a kinetic response.

Russia and China are definitely interfering in the US (to spread discord, ex https://en.wikipedia.org/wiki/Chinese_interference_in_the_20...), so should the US formally declare war against them?

What I do think is that nations should 1) interfere back, and 2) make their citizens more resilient to foreign propaganda. And I specifically don't mean building a firewall. In fact do the opposite: if a firewalled nation is leaking out propaganda, ensure firewall-breaking tools leak in.