The world still needs a policeman. Let’s hope the US doesn’t quit the job | Simon Tisdall

America's record at keeping global order is deeply flawed, but the only winners from its drift towards isolationism will be Xi Jinping and Vladimir Putin

American global leadership took a serious kicking last week. Politicians and pundits on both sides of the Atlantic queued up to condemn George W Bush's and Tony Blair's disastrous invasion of Iraq 20 years ago this month. At the same time, Congress moved to repeal the war powers act that enables a US president to launch military interventions abroad.

In Moscow, meanwhile, Xi Jinping, stringing along his Russian puppet, Vladimir Putin, proposed a new global order to replace the post-1945 US-led model. China's de facto dictator is generously offering to stand guard" over the planet. In Xi's brave new world, subservience and surveillance replace shock and awe. Democracy takes a back seat.