Justifying deadly force

This came from the NY Times of all places:

A terrible thing happened in London last Friday. On his way to work, Jean Charles de Menezes, a 27-year-old Brazilian electrician, was chased down by suspicious police officers. When he tripped and fell, the officers asked no questions and gave him no warning. One of them fired eight bullets point-blank into his head and shoulder and that was that. At first sight, it was an act much more severe than Eldad's, because Eldad had been under attack and shot a man he had good reason to think was armed. Mr. Menezes had hurt no one. On the other hand, it was an easier call. The police saw a man wearing a long coat out of place on a hot summer day jumping over a turnstile and running for a crowded subway train. He did not stop when he had been ordered to do so. Just two weeks before the killing, four suicide bombers had blown themselves up on subway trains and buses in London. Just days before, there were all the signs of another coordinated attack - and the police had reason to believe that bombers were still at large. The long coat on a summer day was just the sort of telltale clue that the police had been told to look out for. A number of suicide bombers in recent years have used such coats to conceal the belt of explosives strapped around their waists. What's more, the police acted under express orders to shoot in the head someone they thought was about to commit a suicide bombing. Suicide charges are usually built to be set off with the flick of the bomber's finger. The terrorist can be disabled, flat on the ground, and surrounded by heavily armed men and still blow up everything around him. So the officer who killed Mr. Menezes did a horrible thing. But he also did the right thing. One of the tragedies of this age of suicide bombers - indeed of any war - is that the right thing to do is sometimes a horrible thing. Remember: there's an essential distinction between us and the suicide bombers. The suicide bombers perpetrate gratuitous horrors. We do terrible things only when it is necessary to prevent something even worse from happening.

A few comments, in no particular order: 1. It now appears that Mr. Menezes was in London illegally, which explains his running from the police. (I can't find a link for this one, although I'm positive I read it somewhere this morning.) 2. On the other hand, as Mark Steyn pointed out, it was a bad neighborhood, the temperature was 61 degrees (not summer), and the police were in plain clothes, which may also explain Mr. Menezes' flight -- although not why he attempted actually to board the subway train. That last ties in more neatly with his fearing deportation. 3. The author of the op-ed quoted above is a former member of the Israeli Defense Force who begins his piece by describing his disgust, as a liberal, when a fellow soldier described shooting a Palestinian fighter who was down in front of him. Despite his intellectual revulsion, you have to agree with his ultimate point -- when push comes to shove, while you may be loath to kill, the terrorist is anxious to kill, and your only defense is to annihilate him completely. It's a horrible travesty that the terrorist imposes on us, the "good guys," the obligation to shoot to kill.