The first civilian trial in America of a Guantanamo Bay detainee showed a "sophisticated justice system" at work, the UK Government's independent terror legislation watchdog has said.
Lord Carlile said criticism of the outcome, which saw Ahmed Ghailani convicted of one count of conspiracy but acquitted on dozens of other counts, including murder and murder conspiracy relating to the bombing of two US embassies in Africa, was political.
The case has been viewed as a test of President Barack Obama's plan to shut down Guantanamo Bay and try detainees in civilian courts, and critics say Ghailani's case undermines it, even though he has been sentenced to 20 years in jail.
Lord Carlile told BBC Radio 4's Today programme: "Mr Obama is himself a very distinguished lawyer. When he decided that Guantanamo detainees should be tried in normal civilian courts he was seeking to ensure proper standards of criminal evidence were applied in these cases.
"That is what has happened. The criticism is simply political and pays scant respect to a sophisticated justice system."
He added: "Here we have a situation in which a proper trial in proper circumstances has taken place. I find it very difficult, as a British lawyer, to understand what is wrong with that.
"If the Obama administration blinks it will undermine further the credibility of President Obama. If Sarah Palin or someone like her was president then we would find the real undermining of a civilised system of justice."