I think it would be nuclear warfare. Nuclear fission is a universal development for any advanced civilization. It would be easy to construct a nuclear bomb in an advanced civilization. Once a few rogue/pariah states start making them, everyone’s screwed.
Making nukes is easy, the only reason we don’t see more nuclear states on earth is because of the international backlash. With a couple more Iran and North Korea’s we’ll likely meet the filter ourselves.
Those who say this are usually frustrated by the increasing number of misunderstandings/miscommunications due to increasing English illiteracy. Its become more difficult to communicate to those around you.
It’s utterly unacceptable behaviour but I believe the issue lies deeper than simple “racism”. I also sometimes find it frustrating from the sheer volume of people that can’t speak English, from coworkers, customers, fellow students, etc. I don’t even live near the border, where the problem is much worse.