US President Donald Trump's apparently coercive threat to force Western allies not to oppose his proposed annexation of Greenland, or face further damage to their trade with the US, is without both parallel and precedent.
We've had some unusual and unexpected economic threats from President Trump over the past year, but I think it is safe to say this exceeds all of them, and takes us into both surreal and utterly dangerous territory.
If taken at face value, it is a form of economic war being levied by the White House on its closest allies.
That's because it targets allies at incredibly short notice and for a cause that essentially could break up Nato and the western alliance.
