military vs. police

[Ignoramus]

Hi, I already asked this and got no response, but I'm going to rephrase it. I hope no one minds.

What's wrong with this notion:

The police are for enforcing laws.
The military are for defending the nation.

In a sense, police are aggressive because they are enforcing the laws of the people, in theory. But the miliary is supposed to be exclusively defensive.

So, military is not to be used in enforcing laws (except during martial law, earthquakes, space aliens invading, etc.), since our laws don't apply to foreign lands.

So so, "preventive war" is a bad idea because the military is not for enforcing our laws on other countries.