Military Alliances in the Twenty-First Century. Alexander Lanoszka

unite in common cause.” Patricia Weitsman (1997: 162–5) invokes the term “tethering” to describe how states form alliances in order to manage each other’s potential hostility, with which they may hope to build friendlier relations over time. The League of the Three Emperors had this purpose. Lasting from 1873 to 1880, the German, Russian, and Austro-Hungarian Empires used this alliance in part to coordinate their activities in the Balkans – a region where Vienna and Moscow had been jockeying for control. Indeed, expectations of more generalized conflict might drive alliance formation. Take, for example, NATO enlargement. In the early 1990s, many observers predicted that much instability would come to Europe because the US and Soviet troops stationed on the continent during the Cold War kept a lid on states’ nuclear ambitions and ethnic grievances (see Mearsheimer 1990; Lanoszka 2020b: 453–5). By incorporating former communist countries like Poland into NATO, some US decision-makers and their Central European counterparts believed that they would enhance the European continent’s prospects for peace. Civil–military relations would proceed along democratic lines, whereas norms of territorial integrity would persevere with nationalist conflict managed and risky defense policies discouraged (Epstein 2005).

      Threat-based arguments allow for the possibility that states form military alliances to deal with internal or transnational threats. Steven David (1991) introduced the term “omni-balancing” to describe situations where states balance against both external and internal threats. By internal threats, David meant potential coup plotters or insurgent groups, which may or may not have outside support (1991: 240–1). Accordingly, leaders might align themselves with a strong state that might threaten their own state’s interests but nevertheless can offer assistance against internal threats. David largely focuses his analysis on the developing countries in the Global South, but his argument can throw a light on alliance patterns in Europe. Apart from managing great power competition in the Balkan region, one reason for the League of the Three Emperors was that it offered a vehicle for coordinating imperial power against the troublesome Polish minority whose country the alliance members had conspired to eliminate in the late eighteenth century. A motivation for creating NATO was to protect anti-communist states from internal subversion and fickle publics (Sayle 2019: 2–7).

Concession-Extraction as Another Standard Explanation of Alliance Formation

A second common explanation of alliance formation looks less at threat perceptions and focuses more on the differences in military power that potential allies can bring to the table. To be sure, the arms versus alliances trade-off mentioned earlier suggests that stronger states should be more reluctant to forge alliances than their weaker counterparts. After all, a strong state presumably can generate enough military power to withstand threats on its own – at minimum, it should be less reliant on others. If weaker states form alliances, then the aim should be to use those alliances to balance against the strongest states.

      And yet, as already noted, the most powerful state today – the United States – has the most allies, many of which lack sufficient military power to deter adversaries on their own. In fact, most existing alliances today are asymmetric – that is, alliances in which military power is largely concentrated in one member. The Mutual Defense Treaty between the Philippines and the United States is one example of an asymmetric alliance. North Korea’s alliance with China is another. Yet these arrangements are puzzling. Should these weaker allies not fear domination by their stronger patron as well? Why would a strong state form a pact with a much weaker state – one that might even be a liability in a war if it is unable to defend itself from another great power? Are such partnerships not superfluous if the great power can rely on its nuclear weapons arsenal as the ultimate source for its security?

One simple answer to all these questions is that asymmetric alliances often reflect mutually beneficial bargains, whereby the strong state and the weak state have overlapping interests but derive different benefits. Consider how the strong state has more security than that of the weak state. The latter may have autonomy, but it does not have security against a particular threat due to its lack of relative military power. Scholars like James Morrow thus argue that the strong state trades away some of its security to the weaker state in return for policy concessions that reduce the latter’s autonomy (1991: 914). These concessions can include hosting military bases and giving access to strategic locations useful for projecting power. The strong state may even win rights to shape the domestic and foreign policy of the weaker state. Alternatively, the strong state could have greater input in shaping the language and content of the alliance treaty – a point to which we will return when we discuss entrapment (Johnson 2015). What the weak state gets in return is a security guarantee against another state that it fears much more, whether for ideological or military reasons. Shared threat perceptions provide the basis for the partnership, but a loss of autonomy on the part of the weaker state seals the deal.

To what extent is this view correct? It seemingly has much going for it. The United States had military bases or forward deployed military assets in all of its most important treaty partners – Canada, France, Germany, Italy, Japan, South Korea, and the United Kingdom – at one point or another during the Cold War. In many allied countries, it still retains a major military presence, although in some cases allies have tried to expel US military forces, or, at least, alter the terms of basing agreements, amid major domestic political change (Cooley 2008). Moreover, Washington and Moscow did occasionally intervene in the affairs of their allies during the Cold War, with the most spectacular episodes being those within the Soviet bloc. The Soviet intervention in the Hungarian Revolution in 1956 and the Warsaw Pact suppression of the Prague Spring in 1968 come to mind. Still, in the 1950s and the 1960s, the US intelligence community quietly contributed funds to Japan’s Liberal Democratic Party (LDP), the conservative political party that would go on to dominate Japanese politics, and has done so ever since (Williams 2020). After the Cold War ended, those states that aspired to join NATO agreed to make a number of changes in their military organizations in order to qualify. Some scholars argue that the more troops that a major power has stationed on a weaker ally’s territory, the more that weaker ally is subordinate to the authority of that major power (Lake 2011).

Nevertheless, the notion that reciprocal bargains exist of the sort postulated here has its problems. To begin with, although a weak state may provide military basing rights to a stronger state, it may not necessarily be a policy concession. In fact, the opposite may be true: forward military basing could be a concession that the great power makes to the weaker state. One reason why the United States stationed as many as a quarter of a million military personnel in West Germany in the Cold War was to strengthen the alliance, rendering Washington’s promises to fight – using nuclear weapons, no less – on its European ally’s behalf more believable by making any major Soviet invasion of its territory less likely to succeed without incurring massive cost. Indeed, the historical record features many allied leaders worrying that the United States might withdraw forces, thereby leaving them vulnerable to external aggression (Lanoszka 2018b). Moreover, it is unclear whether an alliance per se can grant major powers the right to interfere in the domestic and foreign policymaking of their weaker partner. The United States may have intervened in Italy’s general elections in 1948, but this was one year before NATO was founded. The Soviet Union established the Warsaw Pact in 1955, partly in response to West Germany’s incorporation in NATO. But by this time, it had already shaped the domestic and foreign policies of many of the alliance’s members. If anything, Warsaw Pact members were able to assert their status as independent countries by using the formal alliance to demand concessions from the Soviet Union, making the organization less hierarchical over time. Documentary evidence shows Warsaw Pact leaders in Poland and East Germany pushing the Soviet leadership in the Kremlin to intervene in neighboring Czechoslovakia in order to put a stop to the Prague Spring and its liberalizing tendencies (Crump 2015). Amid public criticism that the alliance was too one-sided and domineering, US decision-makers agreed to renegotiate the 1951 Security Treaty with Japan, thus making the alliance ultimately much less intrusive within Japanese domestic politics (Swenson-Wright 2005). The LDP also benefited from the covert support that it may have received from the United States. North Korea arguably conceded little in the two separate alliances that it forged with China and the Soviet Union in 1961.

If asymmetrical alliances