Introduction
Since its inception in 1949, NATO has grown from 12 to 32 members, a process formally known as enlargement. In accordance with Article 10 of the North Atlantic Treaty, membership is open to all European countries so long as they commit to NATO’s principles and meet the Alliance’s requirement for defence spending, along with the political and economic criteria. Historically, Canada has advocated for an “open door policy” and has consistently approved membership requests, most recently being the first country to ratify the Accession Protocols for Finland and Sweden to join NATO in April 2023 and then in March 2024.
Enlargement is an important contributing factor to NATO’s legitimacy and security, as more member countries increase the deterrence against potential external aggression. Arguably, the collective defence clause (Article 5) is one of the most compelling advantages offered to NATO countries; colloquially phrased as “an attack against one is an attack against all”, this clause has only been invoked once in history following the 9/11 terrorist attacks in the United States. The guarantee of collective defence is especially valuable for smaller European countries in the face of Russian aggression; following Russia’s 2022 invasion of Ukraine, three countries — Ukraine, Georgia, and Bosnia and Herzegovina — have applied for NATO membership, none of which has been approved yet. Conversely, the same Article 5 obligation that offers them security also raises the stakes for existing members, who must weigh whether extending this guarantee could overstretch alliance commitments or heighten the risk of direct confrontation with hostile nations. The argument for and against enlargement centers on this trade-off: the promise of security for some creates new vulnerabilities for all.
Analysis
As one of the twelve founding members, Canada’s formal stance on NATO has been as follows:
This statement builds on Canada’s historical contributions to NATO, as well as modern strategic concerns. In 1949, NATO was established as a strict military alliance. It was Lester B. Pearson — then the Canadian Secretary of State for External Affairs — who pushed for a broader vision. Pearson posited that the premise of collective defence worked only under shared political and economic values such as “individual liberty, human rights, democracy, and the rule of law,” as reaffirmed 74 years later by former Prime Minister Trudeau in April 2023 on Finland’s accession to NATO. Enlargement, therefore, would facilitate the spread of democratic institutions and other liberal values, in addition to military power. Though initially an unpopular clause among its members, Article 2 of the North Atlantic Treaty was ratified and is today known as “the Canadian Article”.
Since then, Canada has fulfilled its legacy within NATO as the moral and political conscience by enthusiastically — and often quickly — welcoming new countries into the alliance. There is also a strategic element to this. As a middle power, Canada’s military capacity and defence spending lag behind those of larger countries.
NATO members’ estimated 2023 defence spending in GDP share (%)
Unable to militarily assert its position within NATO, Canada relies strongly on political influence and targeted contributions to expand its influence within the alliance. These include training missions like Operation UNIFIER, niche capabilities in logistics, engineering, and Arctic warfare, and diplomatic bridge-building within the alliance. NATO’s Force Model, in which member states contribute specialized capabilities, provides opportunities for such leadership, especially after enlargement, when new members require training and integration. For example, Canada has led the multinational battlegroup in Latvia since 2017, coordinating contributions from over a dozen allies.
Enlargement also provides a massive relief to Canada’s Arctic security concerns. The High North was formerly privately managed by countries with stakes in the region, but in August 2022, following increased tension with Russia and China, Jens Stoltenberg, NATO’s Secretary General at the time, announced that “NATO must increase its presence in the Arctic.” NATO pledged involvement, calling the High North a “strategic challenge”. This shift in NATO policy follows Russian threats to the region, particularly the Kola Peninsula and Northeast Passage. Arctic countries such as Canada have long been wary of this threat, but there is limited awareness among allies and a lack of resources for Arctic strategies, leaving them to rely on their own military forces as deterrence. The addition of Finland and Sweden — both Nordic nations — shifts the geopolitical center of gravity northward, drawing NATO deeper into the region and thus helping ease this defence burden off independent Arctic countries.
Forward Looking
Canada’s stance on NATO enlargement continues to carry significant policy implications today, particularly when it comes to admitting countries that have a high risk of conflict. Back in February 2022, for example, following Russia’s invasion of Ukraine, Putin claimed that NATO was attempting to influence Ukraine to expand closer to the Russian border. Though Ukraine has expressed interest in joining NATO since 2002, it has not yet gained membership. Opposition primarily comes from the United States, Germany, Hungary, and Slovakia, while a European majority, particularly the U.K., France, Italy, Poland, and the Baltic states, have been more receptive to the idea.
The changing global order adds another layer to this problem. Previously the undisputed world superpower, the United States has pulled back and embraced an increasingly protectionist and isolationist foreign policy, adopting a more confrontational stance toward even close allies. This tension pushes Canada closer to its European allies, but Canada and Europe — though perhaps more ideologically aligned — have different primary security concerns, making formal alliances with defence commitments difficult. Even so, Canada is a valuable asset to European partners as its vast reserves of liquid natural gas and other critical resources enhance both NATO’s resilience and Europe’s energy security. Germany has already shown strong interest; in 2022, then-Chancellor Olaf Scholz visited Newfoundland to finalize an agreement for hydrogen supply from a major wind project on the Port-au-Port Peninsula. Canada’s stance on Ukraine is thus an opportunity to shape its position in the emerging global order: whether to side with Europe and continue supporting high-stakes enlargement or to shift its foreign policy strategy to areas that directly impact Canadian interests.At present, it seems that Canada has chosen the former, which is reflected in its large Ukrainian diaspora population (over 1.3 million) and financial contributions. Since February 2022, Canada has provided nearly $22 billion in assistance, including more than $12.4 billion in direct financial aid — the highest per capita financial contribution among G7 members. However, rhetorical support without substantial investments in defence capacity — especially because Canada’s defence spending falls far below the 2% target — risks Canada’s image becoming symbolic rather than substantive, a criticism already voiced by the United States. All things said, Canada’s credibility within NATO will depend less on the speed with which it endorses enlargement and more on tangible military contributions. Only then can Canada shape NATO’s future enlargement debate in a way that strengthens its own standing within the Alliance.
Photo: NATO. NATO troops training Ukrainian soldiers. Flickr, 2023.
Disclaimer: Any views or opinions expressed in articles are solely those of the authors and do not necessarily represent the views of the NATO Association of Canada.
