Prime Minister Justin Trudeau is hosting a visit from NATO Secretary General Jens Stoltenberg this week. The two are scheduled to tour a military radar site in Nunavut on Thursday before heading to an air base in Alberta on Friday. The tour represents the first visit by a NATO secretary-general to Canada’s Arctic and comes as the military alliance begins to place greater emphasis on protecting its northern flank. Ottawa has long opposed NATO’s greater involvement in the Arctic because of what experts describe as a desire to protect Canadian sovereignty and fend off provocation by Russia. But a senior government official speaking on the record says Stoltenberg’s visit reflects recognition of the impact climate change is having on activity and security in the region. Some experts say easing Canada’s reluctance to work with NATO in the Far North is long overdue, although the exact form any deeper cooperation should take is hotly debated.