Iraq may have been a blood-drenched disaster and Afghanistan a grinding military and political failure. But Libya was supposed to have been different. Nato's war to overthrow Colonel Gaddafi in 2011 was hailed as the liberal intervention that worked.
The western powers might have had to twist the meaning of the UN resolution about protecting civilians, the city of Sirte might have been reduced to rubble, large-scale ethnic cleansing taken place and thousands of civilians killed. But it was all in a noble cause and achieved without Nato casualties.
This wasn't Bush and Blair, after all, but Obama, Cameron and Sarkozy. The people were free, the dictator was dead, a mooted massacre had been averted – and all this without any obvious boots on the ground. Even last year the prime minister was still claiming it had all been worthwhile, promising to stand with Libyans "every step of the way".