“President Donald Trump arrived in Turkey on Tuesday for a summit of the North Atlantic Treaty Organization, as the alliance is squeezed by Russia’s continuing military aggression in Ukraine and America’s growing insistence that NATO members quickly beef up their defense spending,” CNBC reports.“Those pressing concerns come on top of lingering controversies surrounding the U.S.′ war against Iran and its prior attempts to take over Greenland, a territory of NATO member Denmark.”“Trump is a central figure in all of those issues.”Fox News: Trump arrives at NATO summit as Iran rift looms above alliance talks.