I wonder why the police are given so much more weapon's autonomy than the military?
The police, on the other hand, can easily give in to the immediate fear of someone else shooting first: when they are not careful about not escalating, the worst thing that is likely to happen to their side is having to call in reinforcements and having some more bad press that won't add much to whatever they already have. If you want to put it in very crude terms, they are playing war in easy mode and there, many things that are very important to the military are completely irrelevant.
The US military is far more centralised and (despite its many faults) aware of planning for wider strategic issues.
Many police depts don't seem to want to face up to the fact that the tactical problems they have now have root causes in their own short sighted policies, incentives and behaviour. If they carry on like they are, these problems will only get worse.
Other western countries with more centralised police hierarchies seem to put more effort into community relations and other more strategic stuff, even if it means less 'effective' tactics ie less control, arrests and convictions etc.
I think because there is no political will to protect the usual victims of police brutality—indeed, the "tough on crime", and concommitant "tough on people who are in the general vicinity of people perceived to be criminals", mentality, is perenially politically popular.
Of course there is also no political will to protect the usual victims of military brutality, but they can and do (in many cases, to some extent, at least historically) protect themselves, and so it has been perceived that it's necessary to reckon with the possibility of reprisal.
You could usually tell which ones were probably vets too. For example, during one crossing, the Border Patrol guy started trying to have a "sensible chuckle" with me over the fact that some guy had committed suicide on the casino floor (couple of blocks away) the previous day. He even made a fake "hand gun" to mouth motion.
It makes for quite a contrast, particularly at a place like the sleepy border crossing closest to where I grew up; 95% of the traffic through it was log trucks or Canadian locals that crossed over to buy cheaper gas at the station just across the line on the US side.
At a markup. This was 1% for Visa and MasterCard back in ~2006 when I looked into it.
On the U. S. side, it would appear, according to signs at the cash registers, that many U. S. vendors work in a similar manner. The registers signs disappear within tens of miles of the border.
Not policework in the US, though: From what Google tells me, training often lasts less than 6 months. In comparison, in Germany it's normally 30 months, but it can vary from state to state (in a few, it's 24 or 36 months).
This has been going down ever since. At least in my area, new officers are usually straight out of college with a criminal justice major and no military service. (Though I do know several officers who have joined the national guard or the reserves later on.)
Source? A quick Google search shows roughly 3.4MM deployed soldiers in Vietnam and another 4-5MM non-theater personnel.
[1] http://www.infoplease.com/ipa/A0004615.html
[2] http://fivethirtyeight.com/datalab/what-percentage-of-americ...
...the suicide bombings, beheadings, religious wars, and terrorist organizations had something to do with that as well.