Canada’s new government recently raised the possibility of collaborating with the United States on missile defense, suggesting through a wide-ranging defense review that participating in the U.S. missile defense program could “enhance Canadian national security and offer an avenue for greater continental cooperation.” This comes on the heels of a unanimous recommendation from a key committee of Canada’s Senate that Canada “enter into an agreement with the United States to participate as a partner in ballistic missile defense,” and news in 2013 that Ottawa had resumed its glacial move toward contributing to the missile defense architecture.

Put it all together, and it’s not unreasonable to conclude that Canada may be ready – finally – to join the U.S.-led missile defense coalition. If so, it would be a welcome development. Yet given the difficulties Washington has encountered in trying to persuade its nearest (if not closest) ally to participate in missile defense, U.S. officials shouldn’t pop the champagne just yet.

Missing Ally

More than a decade ago, missile defense talks between the Bush administration and the government of then-Prime Minister Paul Martin had progressed far enough that Canadian defense officials publicly announced they were committed to “a mutually beneficial framework to ensure the closest possible involvement ... in the U.S. missile defense program.”

But then Martin had a change of heart and backed out, announcing in 2005 that “ballistic-missile defense is not where we will concentrate our efforts.”

Washington moved ahead without Ottawa, as expected. What was perhaps less expected was the very different reaction Washington’s missile defense plans received in other allied capitals. Missile defense advocates can be thankful the United States didn’t wait on Canada before building a global partnership against missile-armed rogues.

The operative word here is “global.” Enfolding some of America’s (and Canada’s) closest allies and oldest friends, the missile shield that has taken shape since Canada said “no” in 2005 represents an international missile defense (IMD) coalition.

Let’s start in Europe. NATO officially endorsed the IMD system in 2008, calling for a “NATO-wide missile defense architecture” that will extend “coverage to all Allied territory and populations.” In 2010, NATO leaders declared missile defense “a core element of our collective defense” and pledged to “develop the capability to defend our populations and territories against ballistic missile attack.”

Toward that end, Britain and Denmark allowed modifications to early-warning radars to augment the missile shield. Spain hosts a rotation of Aegis missile defense warships. Germany hosts a missile defense operations center. Romania hosts a land-based variant of the Aegis anti-missile system, dubbed “Aegis Ashore.” Another Aegis Ashore battery will be activated in Poland in 2018. Turkey is home to a powerful X-Band missile defense radar, allowing the alliance to scan the horizon for threats from Iran.

Beyond NATO, U.S.-Israeli cooperation dating back to 1986 has yielded a sophisticated, layered defense against missiles, including the Iron Dome system, David’s Sling system and Arrow anti-missile system. Israel also hosts an X-Band radar.

Likewise, Qatar hosts an X-Band radar. The UAE recently became the first foreign government to purchase the U.S. Terminal High Altitude Air Defense System (THAAD). Saudi Arabia, which already deploys a number of Patriot Advanced Capability-3 (PAC-3) anti-missile batteries, is considering purchasing Aegis warships equipped with missile defenses. Likewise, Kuwait deploys a number of PAC-3 batteries. The Kuwaitis, like the Israelis, know the importance of missile defense from firsthand experience: A PAC-3 intercepted inbound Iraqi missiles in the early stages of the Iraq War, shielding the coalition’s headquarters in Kuwait from a decapitation strike.

Australia was an early adopter, signing a 25-year pact on missile defense cooperation with the United States in 2004.

With a wary eye on North Korea, Japan deploys six Aegis ships (eight by 2020), hosts two X-Band radars, and co-developed with the United States a new interceptor missile for Aegis ships. South Korea fields Patriot batteries, Aegis warships and long-range radars – all courtesy of the United States – and is edging toward deploying a THAAD system.

According to a Congressional Research Service report, “Allied countries that now operate, are building or are planning to build Aegis-equipped ships include Japan, South Korea, Australia, Spain and Norway.”

Here in North America, the United States has deployed 30 ground-based interceptor missiles in California and Alaska, with 14 more on the way; activated five THAAD batteries, with more scheduled to come online; and deployed 33 ships equipped with Aegis missile defenses, building toward a fleet of 48 by 2020.

All told, 20 countries, plus the NATO alliance, are part of the emerging IMD coalition. Yet Canada is not one of them. Given Canada’s historic willingness to contribute to Allied efforts – from Normandy’s beaches to NATO’s founding, from the defense of Korea to the liberation of Kuwait, from Afghanistan to Libya – it’s jarring to scan the Missile Defense Agency’s (MDA) growing list of international partners and not see Canada’s name.

It’s time for Canada to join the team.

Risks

The reason so many countries have joined the IMD team is the very same reason Canada is rethinking its agnostic position on missile defense: The chances of a rogue missile attack or accidental missile launch are growing by the day.

Three decades ago, there were nine countries that fielded ballistic missiles. Today, there are 31. Several of them are unstable (Pakistan and Egypt) or unfriendly (Iran and North Korea) or both (Syria). Not coincidentally, the world has seen an increase of more than 1,200 ballistic missiles over the past five years.

Because of the nature of their regimes, North Korea and Iran are the most worrisome of the world’s missile threats. To be sure, other regimes have larger, more lethal arsenals, but those other regimes are relatively rational and stable, which means the old rules of deterrence can keep them at bay. That may not be the case with Iran and North Korea.

In March 2016 and October 2015, Iran tested missiles designed to deliver nuclear weapons – in clear violation of U.N. Security Council resolutions. Dubbed the “Emad,” one of Iran’s new missiles is precision-guided and has a range of more than 1,000 miles – enough to strike U.S. allies and bases in Europe, Israel and across Southwest Asia. In addition, Iran is modifying its Sajjil missile, which will extend its missile reach to 2,200 miles, bringing most of Europe within range. Iran has demonstrated the capacity to loft a rocket into orbit, highlighting “technologies that are directly applicable to the development of ICBMs,” according to the MDA, and has built launch sites for long-range missiles.

However, Iran’s missile reach is not limited to land-based assets. In 2004, Pentagon officials confirmed that Iran secretly test-fired a ballistic missile from a cargo ship. Hiding a Scud-type missile and launcher below decks, the ship set out to sea and then transformed into a floating launch pad, peeling back the deck and firing the missile, before reconfiguring itself into a nondescript cargo ship. As a high-level Pentagon official said at the time, “The big distinction we make between intercontinental, medium-range and shorter-range ballistic missiles doesn’t make a lot of sense if you’re going to move the missile closer to the target.”

This is a regime, it pays to recall, that normalizes terrorism into a basic government function, threatens to wipe neighboring countries off the face of the earth, and invokes apocalyptic scenarios.

Gen. Vincent Brooks, commander of U.S. forces in Korea, recently warned, “We must assume North Korea has the technical capability to mount and deliver a nuclear warhead using ballistic missiles.”

In 2015, Beijing estimated that North Korea possesses 20 nuclear warheads – and soon could have 40. Also in 2015, Pentagon brass concluded that North Korea’s nuclear-capable, road-mobile KN-08 ICBM was operational. “We assess that they have the capability to reach the homeland with a nuclear weapon from a rocket,” Adm. Bill Gortney reported last year.

Equally worrisome, North Korea tested a submarine-launched ballistic missile in 2015 and 2016, making the missile’s range virtually irrelevant.

This is a regime that has tested nuclear weapons on several occasions and warned in 2013 it was prepared to launch “a preemptive nuclear attack” against the United States and South Korea.

“If North Korea would be ready to attack the United States,” then-Prime Minister Stephen Harper conceded in 2006, “that would be a risk for Canada’s national security as well not only because of our common values, but because of our geographical proximity.”

Given North Korea’s technological advances and political unpredictability, that scenario seems more likely now than it was then.

Benefits

Canada’s inclusion in the IMD coalition would yield real benefits for the United States.

For instance, Lt. Gen. Pierre St-Amand of Canada, deputy commander of NORAD, says Canada’s participation would enhance NORAD’s command structure.

Canada could field an Aegis warship, thus serving as an IMD force multiplier, like Japan’s Aegis fleet. Or Canada could dedicate facilities to the IMD effort, like Britain and other allies. As Defense News reports, the Canadian military believes Canada could contribute prime real estate for a bed of interceptor missiles or missile-tracking radars. In fact, the Canadian government contemplated hosting an X-Band radar in the northeastern part of the country during Ottawa’s earlier missile-defense deliberations.

“Canada,” as former Canadian diplomat Paul Chapin has observed, “seems able to support missile defense for others, just not for itself.”

That may change in the coming months. If nothing else, the enthusiastic embrace of missile defense in Europe and beyond should serve as political cover for Ottawa. Instead of staying on the sidelines, Canadian policymakers can tell their ambivalent constituencies, “NATO made us do it.”