What Rules of Engagement?

What with the new London bombings (July 21) the police are out in force dressed in black uniforms, black leather boots, kevlar helmets and vests, with sub-machine guns at the ready, as well as camo dressed National Guard carrying AR-16's.
Heroes must dress the part I suppose; black is "sexy" and the trappings of heroes must be the latest "thing"; HK sub-machine guns and the like.
What do they expect to confront? The Administration has said in the past that "it is better to fight terrorists over "there" than on our own streets". Do they expect to fight terrorists in gun battles on our own streets? If so what are the "Rules of Engagement" and how do the rules impact on the public? Do the police have "shoot to kill" orders, and if so who? Anyone ethnic-looking carrying a large backpack?
Or must the terrorists blow themselves first before they are shot? Or would carrying an AK-47 or a RPG into a subway suffice?
Does being a "terrorist" make a person more dangerous than your run-of-the-mill gun-toting criminal?
Is the public being served by this armed display or is it an expensive feel-good measure?
There must be a few people out there who are scratching their heads, wondering about our reactions to events taking place abroad.
The terrorists are winning their war of terror despite the remonstrations being made; "we won't be intimidated". We are being intimidated, for when a country spends many billions of dollars, attacks a country because of a non-existent threat, restricts travel, searches everyone's luggage, puts machine-gun carrying troops on the streets and in subways, airports, and when government evacuates its offices because of small planes flying near the Capitol, places Patriot ground to air missiles around the Capitol; that is being intimidated.
Reaction to terrorism by closer scrutiny of those who wish to enter the U.S. is appropriate; checking passengers luggage at airports is appropriate; being watchful and adding more numbers of police at subway stations, airports, and other sensitive points is appropriate, revising and updating security measures at nuclear, chemical, electrical installations is appropriate; educating the public to what the real potential dangers are is appropriate: "over-dress", dressing up for war in peace-time in civilian areas is not appropriate;"hyping" the danger, stressing WMDs, that are not remotely possible, over more likely scenarios is not appropriate; creating a "police-state" atmosphere by taking away Constitutional rights is not appropriate.
No government action should be excluded from public oversight. When governments can operate secretly, without some form of public oversight, abuses will crop up and democracy weakened.
No one knows better than the public what is "right". There are too many self-appointed guardians of democracy, who have in the past, and are doing so today, deciding for "us" what "right" action to take and the subversion of our Democracy is the result: Nixon and Watergate; Reagan and Iran-Contra; Bush and the Iraq War; the outing of Valerie Plame--all are good examples of abuses of power. But, I'm straying from the original theme--rules of engagement.
Our government, local and Federal, have not come clean with the American people. Is all the armament for show, intimidation, or for spraying bullets willy-nilly at bad-guys?
Are civilians expendable; i.e., can cops shoot through civilians to get at bad-guys? When can they shoot--preemptively, or only when shot at first? No one has asked and the people have a right to know. One of those "basic" questions the Press has overlooked.