The US military base situated in Greenland was fitted in the 1950s. In order to successfully operate as an adequate early warning system, it has to be upgraded.
If the Thule military base is modernized, then it would be able to intercept long range nuclear-armed ballistic missiles.
Ashton Carter explained that Russia’ long range nuclear-armed ballistic missiles would fly over North Pole, if they were sent to the US.
Russia’s missiles are not the sole threat to the US defense system. A modern radar system is required to defend the country from any possible attacks from Russia, China and North Korea.
This has probably become an issue ever since Russia increased their military presence in the Arctic region. It was even noted by Russian Defense Minister Sergei Shoigu that by the end of 2015 Russia plans to boost its naval fighter and surface-to-air missile regiments in the Arctic.
Unique Arctic version of the Pantsir-S defense system will be developed by Russia.
In addition to this, several military drills were conducted by Russia in the Arctic.