This is your reminder of the great circle routes that ICBM would take to hit the center of the USA from: Iran (Red); Purple (Pakistani) [NB: these are also the routes from most of the Russian ICBM fields]; Russia (Yellow); PRC (Orange); NORK (White). Adjust actual launch sites and actual targets as needed. You can do this yourself on GoogleEarth.
Greenland is the shield for North America from most of the worst places in the world. To have it under utilized as such has always been a threat to the USA since the invention of intercontinental bombers and missiles.
This is by far an exceptional net good. Well meaning people can argue about how we got here, but we got here. No one else made it happen.