If Europe is serious about responsible AI, I think applying pressure to ASML might be their only real option.

True, but now they get to butt heads with the US, who call the tunes at ASML even though ASML is a European company.

We (the US) have given China every possible incentive to break that dependency short of dropping bombs on them, and it would be foolish to think the TSMC/ASML status quo will still hold in 5-10 years. Say what you will about China, they aren't a nation of morons. Now that it's clear what's at stake, I think they will respond rationally and effectively.