Denmark sets a military tripwire. It's a message to Trump more than Russia or China

In military deterrence lingo, what we're witnessing in Greenland is sometimes referred to as the "glass plate" or the "tripwire."

It's a metaphor for breaking the glass — or crossing the threshold — between peace and war.

Denmark announced Wednesday that it is bolstering its troop, naval and air presence in the Arctic island in conjunction with NATO allies.

The Danish Defence Ministry says it plans to deploy additional military capabilities and units for exercises that could include "guarding critical infrastructure, providing assistance to local authorities in Greenland, including the police."

On paper, this token force is being deployed to bolster the island's security in response to U.S. complaints. What is extraordinary, perhaps even unprecedented, is that it serves as message more to the U.S. than it does to Russia or China.

Tripwires are the kind of forces that NATO has deployed in Eastern Europe, including the Baltics where Canada leads the Latvia contingent, to counter any further aggression by Moscow. 

To be clear: The Danish military buildup in Greenland is not a NATO mission — something that would require the sign-off of all 32 member nations, including the United States. 

But a handful of NATO allies, including Germany and Sweden, have signalled they're willing to send troops to Greenland as part of a bolstered presence.

The Danes are currently planning to host a military exercise in the region that could include Canadians, but a spokesperson for Defence Minister David McGuinty said no decision has been made.

"As of this moment, the Canadian Armed Forces are not initiating any new operations in Greenland," said Maya Ouferhat, McGuinty's press secretary, in a statement.

The political significance of joining the Danish initiative would be staggering, said a defence expert.

"Members of the alliance are putting together a tripwire to try to deter Donald Trump, and what that tells you is we are very much in unprecedented times where we could very much be facing tomorrow, next week, next month American troops pointing their guns at Danish troops," said Steve Saideman, a political scientist who holds the Paterson Chair in International Affairs at Carleton University.

"It's to deter the United States from engaging in aggression. That's the only reason why they'd be there. And that sends a strong signal about the intense distrust and fear that these countries have of a country that's supposed to be their protector."

NATO Secretary General Mark Rutte said earlier this week that allies are looking at ways of boosting Arctic security.