Few controversies have divided the British people more than the question of the legality of the war with Iraq.
Among those who believe the 2003 conflict to be unlawful are some of the world's leading experts on international law, who maintain that without a second UN resolution the American and British forces lacked the authority to invade Iraq.
Leading the argument for the British Government is Lord Goldsmith, the Attorney General. He told the Prime Minister that UN Security Council Resolution 1441, which found Saddam Hussein to have failed to disarm, could be used to justify war without a second resolution being passed, if it could be shown that Iraq was still in direct breach.
But it is now clear that even Lord Goldsmith had his reservations about the Government's position because of worries that 1441 did not explicitly set out the conditions upon which military action could be taken.
Yesterday's court martial in Aldershot is further evidence that the question of whether the invasion was unlawful is not merely of interest to international jurists.
Senior military staff were so concerned about the possibility of war crimes charges that they approached Lord Goldsmith for firmer reassurances of the legal position just weeks before the conflict began.
But it is not just on the battlefield that the question of the legality of the war has become so critical. In the courts lawyers have tried to show that peace protesters committing criminal damage should not be convicted of any crime because they are trying to prevent a greater wrong - an unlawful war.
In the cases of the RAF doctor Flight-Lieutenant Malcolm Kendall-Smith and SAS soldier Ben Griffin, who have both cited moral grounds for refusing to take part in the fighting, the answer to the question has far-reaching implications.
Yesterday a court martial in Aldershot sentenced Kendall-Smith to eight months in prison after finding him guilty of five charges of failing to obey a lawful order.
During the trial lawyers for Kendall-Smith argued that the war was unlawful and the doctor was entitled to take a moral stand to disobey an order.
His legal team was prepared to produce expert evidence to show that UN resolutions relied upon by the British and American governments to justify the invasion could be challenged.
But the court, like others before them, dodged this argument by holding that the issue over the legality of the law was irrelevant.
The effect of this ruling on soldiers who take a similar stand in the future could be even graver. The Armed Forces Bill - now going through Parliament - will impose harsh penalties, including life imprisonment, on soldiers who refuse to take part in military occupations.
A little-known section introduces a new tougher definition of desertion so that soldiers who intend to avoid serving in a "military occupation of a foreign country or territory" can be imprisoned for life.Reuse content