OTTAWA — Canada's closest physical neighbours are in an escalating dispute that risks breaking the military alliance that has protected the nations of the North Atlantic for decades. U.S. President Donald Trump keeps talking about annexing Greenland, the Danish territory where Canada is about to open a diplomatic mission. Here's a look at why diplomacy, climate change and natural resources have put Greenland in the global spotlight — and what this war of words could mean for Canadian security. Why is Greenland Danish? Greenland is a mineral-rich island, 80 per cent of which lies above the Arctic Circle. It's home...