"Nuh uh"
Brainsploosh
You're over simplifying the first, and conflating the other.
The MLK protests made change on the back of decades of campaigning together with multiple organisations applying different types of pressure and activism for the same goal, including president Kennedy, and several PR disasters for the opposition.
As for the 2001 attacks, what would you say was their political goal? Was it fulfilled by those attacks? If not, I'd scratch that up as a failed attempt.
Street protests are one of several necessary activities for a change movement. They can help build awareness and let off some steam, but need considerable mass to affect change on their own.
More change happens when paired with organised political action, strikes, obstruction, PR and ofc violence/terror.
The trick is to coordinate the sides towards the goal. Only street protests or only terror won't do anything, but pulling together you did get 8 hour workdays,or more recently grain import regulations (in Poland).
Then again, a million protesters over three months, including transport striking and uncoordinated violence, did not affect the French pension age.
This mostly makes sense if you have need for it, costs and quality won't better automatically. And if demand remains low, there's little incentive to.
Long term the point is usually to lessen dependency on others, for example to enact war, but Dump isn't really dependable for anything long term.
Didn't Dump himself say that it's a negotiating tactic?
He seemed happy to extract low value concessions from Canada and Mexico. Could be he wants an early win, could be he's misleading attention, could be he's appeasing some donors, and could be a fishing expedition to see what concessions he can get from the allies.
Any extraction will enrich himself and cronies, as well as please the autocrats he's serving and/or courting.
Maybe they're arguing self defence?
I'm not convinced the EU is monolithic enough for bad blood to matter, there's enough member states with enough history that someone will always have issues with someone.
What I do believe will be a point of contention though are all the special dispensations the UK have had. With the power balance as it is today, UK might have to face membership on equal terms with the other member states this time around.