Lol, like their drug prohibitionism never spilled over to other countries?
Like it or not they influence policy everywhere. Plus if they opt out of environmental policies (even more than they already do), they absolutely have the power to fuck up the Planet for everybody else.
I won't even touch military matters as they should be self-obvious.
How much more direct can it be? Trump moving in with you?
may a better species rise from the ashes of our civilization