The Home Team looks beyond the immediate politics surrounding President Trump's Greenland agreement and asks whether its real significance will only become clear decades from now. The pact substantially expands America's military presence while Greenland remains within Denmark. Signed September 22, the agreement expands U.S. military access and adds defense areas at Narsarsuaq and Mestersvig while maintaining Pituffik Space Base. Denmark says the framework also strengthens NATO's broader responsibility for Arctic security. The long-term argument centers on a changing Arctic. Greenland's geography makes it important for North American and North Atlantic defense, while increasing Russian and Chinese activity has made the region a greater strategic priority for Washington and NATO. The deal also resolved, at least for now, a diplomatic standoff created by Trump's earlier push to acquire Greenland. Instead of transferring sovereignty, the final agreement expands American military access while recognizing Greenland's self-determination within the Kingdom of Denmark.