Originally Posted by
Subby
They don't have too be. A bunch of soldiers or potential soldiers in your country represents a problem.
It's hard to see from within a country, but looking at the US from outside, on a geopolitical analysis the greatest strategic threat to the United States of America that exists is actually Mexico. Threats on your continent are far more dangerous than threats across an Ocean. That leaves Canada and Mexico, both large economies and historically large military powers, both of which have previously invaded the US.
Canada has a problem with invasion because the land routes are relatively narrow and obvious choke points despite the large border.
Mexico does not have this, there is no natural border between the US and Mexico, and historically it's been in flux. Which means it can go North or South again.
There are a lot of Mexicans in the Southern US. Eventually there will be more Mexicans in more places then not, regardless of intent, that is a demographic replacement. If your people are the only people on that land, then you are 90% of the way there to owning it. This is how Russia has taken over land in recent history, just flood the area with Russians.
Eventually the people there just start living like they would in Mexico and any semblance of the US is gone, if all the local police and political apparatus are Mexican and fly Mexican flags and speak spanish, who owns the land? Who's going to do anything about it?
If you have a container of dirt and put some water in it you still have dirt. But if you continue adding water, eventually you will have a container of water with some dirt floating in it. The fundamental defining quality that is "container of dirt" has been changed.
The issue with "military age males" is that they are the ones most capable of violence and intimidation, whether overt or covert. They are more noticeable, and have more of an affect then Mexican Grandmas.