The United States has proposed to develop the “Golden Dome,” the most ambitious missile defence system ever envisioned. The aim is to build a multi-layered “shield” from the ground into space, capable of stopping everything from drones to hypersonic and nuclear missiles.

Canada is reportedly in talks about joining, with Trump floating a price tag of $71 billion. While no formal commitment has been made, Canada is already contributing to North American defence through upgrades to its North American Aerospace Defense Command (NORAD) radar and command systems, and through ongoing military consultations. 

Supporters see it as a bold investment in North American security. But critics warn it could be technically unproven, strategically risky, and politically destabilizing—especially with plans to deploy weapons in space.

Debate continues about whether to say yes, or to maintain Canada’s historic decision to stay out of U.S. missile defence systems. Three big questions:

  • Does it make Canada safer — or less secure?
    Golden Dome raises concerns it could provoke nuclear adversaries, not deter them.
  • Can Canada support space-based interceptors while advocating norms to prevent an arms race in outer space?
    Partnering in the Golden Dome program could undermine our credibility on space governance and security.
  • Is Golden Dome the best way to invest billions —especially when it may not work?

What might Canada be trading off by contributing to a system with uncertain benefits?

What is the Golden Dome?

Golden Dome is the most expansive missile defence plan the United States has ever proposed. 

President Trump issued Executive Order 14186,  “The Iron Dome for America”on January 27, 2025—directing the U.S. Department of Defense (DOD) to develop “a next generation missile shield”—later renamed “Golden Dome” — that vastly expands U.S. missile defence. 

The order proposes a large-scale, multi-layered air-and-missile defence system intended to provide nationwide protection against all types of missiles, drones, and other aerial threats using a mix of radars, sensors, and interceptors, both on the ground and, for the first time, in space.

The most controversial feature is a proposed network of armed satellites intended to shoot down missiles in their first moments of flight. Critics warn this would cross a dangerous threshold by weaponizing space, increasing the risk of nuclear escalation and strategic instability.

Unlike previous U.S. missile defence systems, which focused on regional threats from states including North Korea and Iran, the Golden Dome would target advanced nuclear arsenals from rivals like Russia and China. This shift expands on policy changes initiated with the 2019 Missile Defense Review.

Canada’s territory and over‑the‑horizon radars are indispensable to this defence‑in‑depth approach; without them, Golden Dome couldn’t reliably track missiles from Russia or China.

What’s at stake for Canada?

  • Cost: Ottawa is reportedly in talks to join the Golden Dome, but the costs are murky. President Trump’s  pitched cost of US$71 billion is more than the total of Canada’s entire NORAD modernization plan and would rival federal investments in climate or housing.
  • Space policy: The Golden Dome signals a major shift in the military use of space for missile defence, moving from passive functions like sensors for surveillance and tracking to the deployment of space-based weapons. This shift runs counter to Canada’s longstanding support for international efforts to prevent an arms race in outer space and promote responsible behaviour in space.
  • Risk of escalation: The Golden Dome marks a major shift in focus from defending against threats by smaller so-called “rogue states” such as Iran and North Korea, to threats by nuclear powers like China and Russia, which experts and the Chinese Foreign Ministry warn can provoke new arms races and increase nuclear tensions.
  • Democratic accountability: There has been no public debate in Canada. No vote in Parliament. No explanation of how participation would affect Canadian foreign policy or commitments to international peace and arms control.

How much will the Golden Dome cost Canada?

U.S. President Trump has floated the possibility of Canada contributing US$71 billion to the Golden Dome program. While the details and financial implications of participation remain unclear, the program could become one of the largest military investments in Canadian history.

For comparison, that’s nearly double the cost of Canada’s full NORAD modernization plan. Meanwhile Canada has only invested roughly CDN$6.6 billion in national climate adaption since 2015.

And costs could grow significantly. While President Trump has pegged the system cost at $175 billion, the Congressional Budget Office estimates that building and operating the space-based component alone could cost between $160 billion and $542 billion over 20 years. This makes Golden Dome one of the most expensive military systems ever proposed—and that’s without including protection for Canada’s vast territory or scattered population centres.

Will the Golden Dome even work?

Missile interceptors are missiles themselves, which are meant to strike incoming missiles—or ‘hit a bullet with a bullet.’ Doing this from space, at hypersonic speeds, across vast distances is extremely difficult. After decades of research and the spending of hundreds of billions of dollars, no system today can reliably stop a large-scale missile attack. The Golden Dome would be no exception.

The Golden Dome faces man serious technical challenges. Each aerial threat presents its own distinct tracking and targeting challenges that must be integrated into the system. For example, hypersonic missiles and manoeuvrable warheads are designed to evade or confuse defences. Space-based interceptors must be precisely pre-positioned directly over launch zones, reach extreme speeds, and operate with perfect timing and reliability—all while avoiding decoys, evasive manoeuvres, and other countermeasures.

The American Physical Society estimated that 1,600 interceptors would be needed to defend against a single missile from North Korea. Providing 24/7 protection from Russian or Chinese missiles would require tens of thousands of interceptors in orbit, an astronomically expensive and politically contentious prospect. 

Lifecycle cost estimates suggest that even defending against a few missiles would cost in the hundreds of billions—potentially over a trillion—dollars, far beyond any realistic investment plan. Meanwhile, the US Government Accountability Office warns that existing systems are struggling with testing realism, cost overruns, and limited real-world performance. As Arms Control Today notes, the “dome of delusion” masks the many strategic, technical, and fiscal failures of prior missile defence efforts. 

Does Canada already participate in U.S. missile defence?

No. Canada shares early-warning data via NORAD, but it has never formally participated in US ballistic missile defence (BMD) programs. 

In 2004, Canada expressed interest in joining US BMD but officially rejected participation on February 24, 2005, citing concerns over sovereignty, strategic stability, and space weaponization. Canada shares early-warning data but has no role in intercept decisions. In the case of an incoming ballistic missile, the US Northern Command would make decisions independently of Canada.

Canada’s non-participation in US BMD has been reviewed, but there has been no shift in policy.  

Strategic and governance risks

For Canada, joining the Golden Dome program could carry serious long-term risks that go beyond defence procurement and touch on global security, diplomacy, and international law:

  • Undermining nuclear stability: By targeting advanced missiles from major nuclear powers, the Golden Dome could destabilize the delicate balance of nuclear deterrence—long anchored in mutual vulnerability—and provoke adversaries to expand or modernize their arsenals in response.
  • Fueling a space arms race: The plan’s space-based interceptors would shift space use from surveillance to weapons. Participation would contradict Canada’s longstanding support for preventing an arms race in outer space and could damage its credibility on disarmament and space governance.
  • Increasing crisis instability: Missile defence systems can create a dangerous illusion of invulnerability. In high-stress scenarios, they may increase the temptation for pre-emptive action or lead to miscalculation—especially if adversaries doubt the system’s true capabilities.
  • Raising legal and diplomatic concerns: While the 1967 Outer Space Treaty prohibits weapons of mass destruction in orbit, it remains silent on conventional weapons. Golden Dome would exploit this legal gap, intensifying divisions at the United Nations and stalling international efforts to prevent conflict in space.

What about the Arctic?

Defending the Arctic is a priority for Canada. Threats range from climate change and infrastructure gaps to new surveillance and military activity by other states. But Golden Dome is not an Arctic strategy.

Current U.S. missile defence systems are intended to protect major American population centres. They are not designated to defend Canadian territory, let alone the Canadian Arctic, which would require a significant increase in capacity. And even with improved detection, existing sensors struggle to track low-flying or manoeuvrable threats like cruise missiles and hypersonic glide vehicles—threats particularly relevant in the Arctic environment.

That’s why Canada is already investing nearly $40 billion in NORAD modernization, including Over-the-Horizon Radars to detect threats approaching from the north, satellite communications and tracking, and all-domain awareness to monitor air and maritime activity in remote regions. 

Canada is also prioritizing Integrated Air and Missile Defence (IAMD) capabilities, a layered approach to tracking and defeating regional threats like cruise missiles, drones, and other low-altitude airborne systems. 

Even with stronger surveillance and tracking capabilities, space-based missile defence still faces serious limitations in the Arctic. And by fuelling strategic competition, increasing the risk of miscalculation, and provoking pre-emptive military or even nuclear escalation near the poles, it could actually make the region less stable.

What about Canadian industry?

Canada’s defence sector is already contributing to NORAD modernization and Arctic defence programs focused on surveillance and early warning in a variety of ways. Inuit-owned firms like Nasittuq operate key Arctic radar sites. Canadian companies such as General Dynamics Mission Systems Canada support command-and-control, satellite, and precision systems. Defence Research and Development Canada (DRDC) leads national innovation in radar and surveillance technologies.

While Canadian firms like Magellan Aerospace already supply components to U.S. missile defence systems, the Golden Dome’s proposed space-based systems represent an uncertain industrial path. The program has not yet outlined a clear industrial pathway for allies like Canada, which has not been invited to co-develop any component. U.S. ‘Buy American’ procurement may also limit foreign participation. Political controversy over space-based weapons could further reduce domestic support.

Are we being left behind?

Supporters of U.S. missile defence warn that Canada’s refusal to join US missile defence systems—including the Golden Dome—risks losing our say in continental defence. A recently leaked memo warns that Canada’s refusal to participate in U.S. ballistic missile defence in 2005 has damaged its standing as a security partner, potentially reducing its influence in allied decision-making and access to classified defence data—unless the Canadian government engages in formal participation in such programs. But the reality is that the system depends heavily on Canadian territory and infrastructure for long-range radar and missile tracking. Without this assistance, its ability to provide defence in depth is significantly diminished.

Some claims that Canada is losing influence rest on the assumption that participation guarantees strategic input. But real influence comes from credibility, leadership, and strategic alignment, not simply buying into every allied system.

According to many analysts, the Golden Dome is technically unproven, strategically destabilizing, and politically divisive. It raises major questions about cost, effectiveness, governance, and alignment with Canada’s defence priorities.

Participation is not all-or-nothing. Canada is already contributing to continental defence through NORAD modernization, Arctic surveillance, and integrated air and missile defence—investments that reinforce deterrence, strengthen resilience, and reflect long-standing Canadian policy principles and preserve greater strategic flexibility.

Participation in Golden Dome would mark a significant departure from this approach. It could reshape Canada’s role in space security and arms control, with limited assurance of influence or return.

Joining the Golden Dome program would raise costs for Canada without guaranteeing control. The system will be designed, led, and directed by the U.S., leaving Canada a junior partner in a risky strategy over which it has little say.