NATO should have learned from its 2004 inclusion of the Baltic states, militarily weak and exposed countries whose defense now constitutes a major, expensive, and perhaps unachievable military requirement. Instead, the expansion of membership has continued. Albania and Croatia joined in 2009, Montenegro in 2017. Now there is talk of bringing in Bosnia or North Macedonia. But expansion weakens the alliance rather than strengthening it. It commits NATO to defending vulnerable, and often politically fragile, states while adding little to NATO military capabilities. It weakens U.S. domestic commitment by provoking resentment from NATO-skeptics. Finally, it constitutes yet one more jab at Russia, increasing its sense of encirclement and paranoia. It’s time to stop NATO expansion.
Genesis: NATO’s Search for a Post-Cold War Purpose
The problem has been building for a generation, arising in the 1990s when NATO began looking for a new purpose at the end of the Cold War. NATO’s initial purpose had been clear as Lord Ismay, its first secretary general, had stated: NATO would keep the Soviet Union out, the Americans in, and the Germans down. By that, he meant that the alliance would block the Soviets from moving further west as they had the military power to do, tie the Americans to Europe to prevent disengagement as had occurred after World War I, and prevent the Germans from becoming militarily aggressive as had happened twice before. In this, the alliance succeeded brilliantly.
Its stable membership reflected its clear military purpose, the 14 original members all being on board by 1955. From then until the end of the Cold War, only Spain joined this cohesive bloc.
When the Cold War ended, none of the three original purposes were still valid. The Soviet Union was on the ash heap of history, the Americans were firmly tied to Europe, and the Germans were a stable and trustworthy democracy. Rather than dissolve such a successful alliance and disrupt all the institutional arrangements that had built up over 40 years, the alliance turned into a kind of military arm for European integration. Thus, NATO reached out to the former Soviet satellites in Eastern Europe, initially offering them a kind of associate membership (the “partnership for peace”) and then permanent membership. The national security establishments in NATO countries strongly supported this shift in purpose. They still do, as seen in a 2016 open letter published in War on the Rocks when Montenegro sought membership.
Defending Fragile and Vulnerable States
Every state added to NATO brings a strategic liability. The Baltic states, added to the alliance so casually during a period of U.S. hegemony, exemplify this problem. The alliance is pledged to defend them, but their geographic position — far from NATO military power centers but close to Russia’s — makes them almost undefendable. The results of U.S. wargames have given reason for pessimism, projecting that the Russians could capture the Baltic capitals of Riga and Tallinn within 60 hours. NATO has scrambled to deploy units forward to the Baltic states and to increase its low rate of military spending to build capability that backs up its new treaty commitments. Even so, mounting more than a tripwire defense may be impossible.
New strategic liabilities can be offset by new military capabilities. However, while Poland and Romania brought large militaries with real capability, most new additions did not. Albania has only 8,000 members in its military forces (active and reserve), Slovenia 9,000, and Montenegro 2,000. These are small countries with weak militaries and essentially no ability to project power outside of their borders. They are consumers of security, not providers.
The weakness of new members might be offset by the capabilities of old members, but, as President Donald Trump never tires of pointing out, NATO defense spending is low. Indeed, in 2011 Secretary Gates bemoaned the “demilitarization of Europe.” Average NATO spending for the European members is only 1.5 percent of GDP, up slightly from a 2015 low of 1.42 percent. By contrast, the United States spends 3.5 percent of GDP (using NATO’s methodology). Even the Baltic states, which arguably face an existential threat, spend barely two percent, though, to be fair, they have doubled their spending since 2011. Germany, having the largest economy in Europe, might be expected to take up a major part of the burden but for reasons historical (two world wars), political (threats are far away) and social (a deep distrust of military power), its military spending is low (1.2 percent of GDP), the readiness of its forces is poor, and its ability to deploy forces extremely limited.
By some other measures, alliance members look a little better. A recent CSIS study noted that, although military spending is low, some NATO members have contributed substantially to peacekeeping missions and strengthening the alliance’s mechanisms for moving forces east. Nevertheless, deployable and effective military capability is far below what a rich collection of countries should be able to produce.
The new states are not just militarily weak but, often, politically weak also. The Baltic states have large Russian minorities who might be turned against the government in a showdown with Russia. The Balkans are a tangle of interstate tensions and internal divisions. Montenegro barely suppressed a recent military coup. Serbia, which sits next to several NATO members, is unreconciled to its loss of status after the breakup of the former Yugoslavia. Albania has ethnic enclaves in other countries, and some Albanians dream of a “greater Albania.” Bosnia is still bitterly divided by ethnic tensions.
Weakening Domestic Support for Alliance Commitments
Trump has become notorious for his hostility to NATO and his confrontations with Allied leadership. When Montenegro joined the alliance in 2017, Trump asked the obvious questions: Why should his son defend this country and would these “strong and aggressive [Montenegrin] people” start “World War III”? The national security intelligentsia was horrified, but the question was reasonable. Most Americans could not find Montenegro on a map if their lives depended on it, and the Balkans have been a source of instability for centuries. If the problem were one particular president, the alliance might just wait for a change of administration. However, Trump put his finger on an issue that bothers many Americans. While 80 percent of Americans support NATO in concept, half believe that the United States should not be required to defend NATO allies from attack if they do not spend more on defense. Academics have questioned the value of alliances because of the commitments they entail. Politicians on the left, like Sen. Bernie Sanders, have questioned the cost. Discontent with allies is, therefore, a permanent part of U.S. politics, and alliance expansion exacerbates this discontent.
Provoking the Russian Bear
Finally, expansion provokes the Russians. Russia argues that the United States had promised not to move the alliance east when the Cold War ended, a claim with some support in declassified archives. Although this interpretation is disputed by Western analysts, the Russian perception of Western perfidy persists. This Russian perception was strengthened by the 2011 intervention in Libya where NATO, given a mandate to protect civilians, instead supported a military overthrow of Muammar Qaddafi.
Beyond perceptions, the Russians have some objective facts on their side. Military analysts are often told to “turn the map around” and imagine how the world looks to an opponent. What the Russians see is this: NATO and Ukraine now occupy approximately the spring 1942 frontline between the Soviet Union and the Wehrmacht, except for Belarus. While NATO views this as benign, the Russians cannot help remembering the last time an adversary got this close. While Western audiences dismiss as propaganda Putin’s denunciations of fascism in neighboring countries, many Russians share Putin’s alarm about western intentions.
Towards a More Sustainable Future
Cessation of expansion does not mean that other countries must be left out in the cold. The “partnership for peace” still exists as a way to link countries to the alliance without formal membership. Such a mechanism could be employed in the future, not just for Bosnia and North Macedonia but also for Georgia, Kosovo, Finland, Sweden or any other country that might become interested in membership when they feel threatened. These partnerships extend NATO’s influence and enhance the capabilities of the partner to resist aggression without burdening the alliance with the treaty obligations or provoking domestic controversy.
Ultimately, though, NATO is not the United Nations where universal membership is a goal. It is a military alliance that requires some degree of internal cohesion for effectiveness and commits its members — especially its largest member, the United States — to use force on behalf of the others. Continuous expansion makes the alliance vulnerable to eventual collapse as military demands increase, internal cohesion fractures, Russia finds more weaknesses to exploit, and U.S. commitment declines.
Jennifer Lind and William Wohlforth make this point as part of a broader strategic argument that, “Washington should … concentrate its attention and resources on managing great power rivalries. As part of this, the United States should reduce the expectation that it will take on new allies.” (War on the Rocks fans can hear a discussion of this article in a recent Net Assessment podcast.) Michael Mandelbaum makes a similar argument in proposing containment of Russia, China, and Iran. He argues that “Adopting containment as a strategic frame would help restrain Washington’s occasional impulses to do more (try to transform other societies) or less (retreat from global engagement altogether).” The bottom line of both strategies is the same: NATO needs to stop expanding if it wants to survive.
Matthew Cancian served as a captain in the Marine Corps from 2009 to 2013, deploying as a forward observer in Operation Enduring Freedom. He is currently a PhD candidate at MIT and a non-resident fellow at West Point’s Modern War Institute.
Mark Cancian (Colonel, U.S. Marine Corps, ret.) is a senior adviser with the CSIS International Security Program. Colonel Cancian spent over three decades in the U.S. Marine Corps, active and reserve, serving as an infantry, artillery, and civil affairs officer and on overseas tours in Vietnam, Desert Storm, and Iraq (twice).