[RoughDobermann]

If the citizens do it, it's called murder

Right, but it shouldn't be in my opinion. They are invaders.

If the government does it, it's called an extra-judicial killing

If the government does it (which it won't), it would/should be called stopping an invasion.

[Major_Risktaker]

Before crossing the boarder illegal immigrates could use this book. However, reading English first would help.