Sweden and the United States recently agreed to expand their practical defence cooperation, and a similar US-Finnish accord is under discussion. Should Finland and Sweden now seek a US defence guarantee in lieu of NATO membership? Here’s why Washington would not like the idea.

The idea of Sweden and Finland seeking mutual defence treaties with the United States in lieu of joining NATO might seem like a logical step. It would go beyond the essentially technical agreement already signed by Sweden and the United States – a similar US-Finnish agreement is under discussion – to broaden bilateral practical cooperation in areas such as military training, information sharing, and research. After all, why bother seeking a consensus from 28 allies (29 once Montenegro joins) if it’s really America’s commitment and capabilities that underwrite Article 5, the NATO Treaty’s collective defence provision?

But there’s a problem: Washington would not accept the idea. Here’s why.

The Alliance was never just about binding the United States to Europe. From Article 5 to its multinational structures to its experience in operations, the Alliance reflects a “one for all, all for one” ethos that binds Europeans and Canadians to cooperate with and, if necessary, defend one another. As seen after the September 11, 2001 terrorist attacks in New York and Washington, NATO also can serve to aid Americans under threat.

The collective nature of the Alliance has invaluable advantages for the United States. It tells Americans they are not alone in deterring aggression and would not be alone in defending a threatened ally. It also provides the political, legal, and practical framework for US forces based in one allied nation to be readily available to help another.

True, US leaders periodically and strongly urge Europeans and Canadians to increase their defence capabilities. Three US defence secretaries have since echoed then-secretary Robert Gates’ warning in June 2011 that NATO risked becoming a “a two-tiered alliance”, divided between “those willing and able to pay the price and bear the burdens of alliance commitments, and those who enjoy the benefits of NATO membership … but don’t want to share the risks and the costs”.

Still, the Alliance has proved more resilient than its detractors predicted. For example, NATO decided at its recent Warsaw Summit to deploy, as of 2017, four battalion-sized multinational battlegroups in the Baltic states and Poland. Led by the United Kingdom, Germany, Canada, and the United States, these formations will include rotational units from Norway, Denmark, the Netherlands, France and Belgium. This virtually ensures that any Russian aggression against an ally in this region would quickly be met with a collective response.
Furthermore, under Article 5, each NATO member has an individual as well as a collective obligation to assist an ally under attack. Hence, if NATO as a whole were slow to react, the United States would still be obligated to render assistance.

America’s vital stakes in the transatlantic relationship make it inconceivable that an armed attack against one or more of the NATO allies would not trigger a determined US military response. America’s geostrategic interests would also force it to act: think of how Japan and South Korea, which have mutual defence treaties with the United States, would react if the commander-in-chief were to order US forces to stand aside as a European ally is overrun.

Of course, the United States, Sweden, and Finland want to avoid such a conflict in the first place, which further explains why talk of bilateral defence guarantees makes no sense. It would weaken deterrence by signalling to other allies that the United States has lost faith in their commitment to collective action. This would encourage Russia to ramp up its provocative behaviour aimed at fracturing transatlantic solidarity.

Bilateral guarantees would encounter resistance in Washington. For example, Pentagon officials would be wary about setting a
precedent by creating unique defence arrangements with Sweden and Finland separate from, or duplicative of, NATO channels. Added to this, US Senators, who must give their advice and consent to treaty ratification, would be sceptical of bilateral treaties with Sweden and Finland as well; many would see the balance of risks and responsibilities as a lopsided deal, favouring those countries’ interests rather than enhancing transatlantic burden-sharing.

Some might suggest a variation of the bilateral treaty idea: “interim” but formal US guarantees to protect Sweden and Finland during the gap between their eventual decisions to seek NATO membership and completion of the accession process – a period when Russia would likely flex its muscles to try to reverse those decisions. (“Secret” guarantees, rumoured to exist with Sweden during the Cold War, are a fiction in the age of WikiLeaks and Russian hackers, and they wouldn’t have the desired deterrent effect.)

In theory, the “interim” guarantees would be relatively short (perhaps a few months) given the quality of the Swedish and Finnish defence forces and their already close working relationship with NATO. But they would still be problematic. Washington, Stockholm, and Helsinki would need to agree on the duration of their separate guarantees, since the NATO accession process has no deadline; provisional operational planning for the joint defence of Sweden and Finland; and procedures to amend or abrogate the guarantees if, for some reason, the Swedish and/or Finnish government(s) changed their mind on accession.

To be clear, these obstacles to bilateral defence guarantees do not reflect US or NATO disinterest in enhanced cooperation with Sweden and Finland. Indeed, as NATO Deputy Secretary-General Alexander Vershbow stated during a recent visit to Helsinki: “A crisis in the Baltic region could very well affect both NATO member countries and Finland. NATO could decide to respond to the crisis by protecting allies and by helping a close partner”.

But his distinction between “allies” and “partner” was no doubt deliberate. Unless and until Sweden and Finland choose to join the former, they will remain the latter. A bilateral treaty with the United States is not a third option.