The warrant for Almog's arrest was issued under the Geneva Conventions Act 1957, which was passed, somewhat belatedly, to allow Britain to ratify the four Geneva Conventions of 1949 for the protection of victims of war. Our courts have "universal jurisdiction" under the Act: under English law, it is an offence for anyone to commit a "grave breach" of one of the conventions. 

There is an important safeguard against inappropriate use of the Geneva Conventions Act. English law says that criminal proceedings in respect of alleged offences occurring after August 2001 cannot be instituted without the Attorney General's consent.

But that safeguard does not extend to arrest. Anyone may obtain a warrant from a magistrate without notice by producing information, substantiated on oath, that a named person is suspected of a serious offence. Broadly speaking, the police must then arrest the person concerned. 

At one stage, it looked as if ministers were willing to amend the law by giving the Attorney General a veto over arrests in Britain for war crimes allegedly committed abroad. But the government has failed to make good that pledge, despite a recent legislative opportunity. It should now do so. There should be no power of arrest in cases where there is no realistic prospect of a trial. And no Attorney General would consent to a prosecution that would force the only democracy in the Middle East to withdraw its diplomatic relations.

Unless the law on arrest is changed, Britain will lose any remaining influence it still has as an honest broker in the region. And the next generals to find themselves victims of lawfare in Britain may be visiting Iraq war veterans from the United States.