Two British citizens have been killed by their own Government without the slightest attempt at legal due process; killed by a country which officially does not even have the death penalty. They were supposedly killed for plotting to kill the queen. Of course, had they succeeded in killing the queen the penalty would only have been life in prison.
Bang! You're dead!
This blog has no real objection to muslim terrorists being killed, and plenty of private individuals have travelled to the Levant to help kill ISIS fighters, mainly by joining up with Kurdish forces, and there has been no great outcry or legal sanction when they got back to the UK. (Unlike those who travel to join ISIS who get prosecuted.)
It's not a new thing for HMG to kill its own citizens. In 1988 three unarmed IRA members were killed in Gibraltar by the SAS. Throughout the "troubles" in Northern Ireland arrests of suspected terrorists were divided into "hard" and "soft". In a soft arrest the suspects were actually arrested but in a hard arrest they were simply shot dead and there was no legal consequence for the killers. (After several members of the UK government were killed in a Brighton hotel in 1986 by the IRA the army in Northern Ireland were given free rein to kill at will.)
However there is a new thing here. For the first time the Prime Minister has personally ordered an execution (two in fact.) There can be absolutely no pretense that it was necessary as a national security measure - the two terrorists were nowhere near British territory. "Dave" wanted them dead so they died. One imagines though, that he was egged on by the intelligence services and the RAF, very keen to try out their comparatively new toys.
This may not be the zero cost operation that Cameron imagines. The two terrorists are likely to have family back in the UK. There could be court cases; demands for compensation; allegations of murder even. Cameron may discover the long term legal ramifications outweigh the fun he had on the day