The first question is what Greenland is worth. Finance students will recall two ways to approach that in an M&A scenario. One is “intrinsic valuation”. The American Action Forum, a think-tank, totted up Greenland’s barely tapped mineral reserves at market prices, applied a probability weighting of sorts, and arrived at $186bn. Double that to factor in the value of owning a region critical in a theoretical war with Russia, and call it $370bn.