I think that's the entire point of any army :). In this instance I guess the military police would be responsible though.
It's a centralized system, and every account holder is fully identified to the government (even with DNA samples IIRC). The kiosks likely keep the logs and upload them when a connection can be made. Then the data get collected and compared centrally, and any discrepancy would show up. At least that's how I understand the "batch processing" remark in the wiki page.
Not sure a whole book is needed, it seems fairly straightforward to show that society is based on threats of violence.
If you don't pay someone, that someone can go to a judge. If you indeed did something illegal (e.g. if you did a double spend, money forgery, whatever) you should be declared guilty and ordered to pay the damages plus perhaps a fine. If you don't do that, the amount due will increase and eventually you get ordered to jail. If you don't go voluntarily, they will make you. Of course everything comes down to force and eventually violence in the end. Why else would you comply with things that don't please you? (Because you're an honest party, okay, and the vast majority of people are, but not everyone is in the privileged position where they have what they want without applying dishonesty.)
Even if you think to solve it with technology, preventing a crime is indeed better than detecting and punishing one, but let's say it's impossible to detect the double spend ahead of time and your technological solution only finds out that there was a double spend after the fact. What's it going to do, block your card from now on? In the end, it will still have real world consequences for you. Taking away someone's card, through physical or technological means, it's all more or less the same thing.
It doesn't prevent from physical torturing that can be used to steal your coins. I've already seen a bunch of news about missing or killed people in this field. The creator is also probably dead.
