Some of the most vulnerable US allies, located near regional revisionists in Europe and Asia, are beginning to rethink their security strategies. A combination of obstreperous revisionist powers in their vicinity and a distracted and solipsistic United States far away is in fact awakening security fears dormant for decades. Poland and Japan, among others, are embarking on defense modernization plans and are adjusting their postures to reflect new regional realities. Most interestingly, some US allies are acquiring, or planning to acquire, weapons capable of striking inside their rival’s territories.
The United States should encourage such rearming. Well-armed frontline states, capable of hitting a common rival on its own territory, are a source of stability in a US-led alliance. They develop a missing and necessary component of the deterrence that undergirds regional stability, strengthening local defense and enhancing US extended deterrence.
In particular, offensive capabilities in the hands of the most vulnerable allies address two sets of problems. First, they reinforce indigenous deterrent capabilities that are especially needed to deal with the threat of small, localized attacks by the nearby revisionist power. They also give the targeted small or medium-sized state the option to force the enemy either to escalate to an uncomfortable level or to continue a limited war under more difficult conditions. Second, offensive capabilities in the hands of frontline allies reinforce the credibility of American extended deterrence by breaking the hostile A2/AD bubble, thereby lowering the costs of projecting power to the battlefield.
The nature of the threat presented by regional revisionist powers – China and Russia – makes such offensive capabilities more necessary than in past decades. The Western alliance system in Europe and in Asia cannot rely on a defense in depth, trading space for the time required to activate the allies and to project their forces to the frontline. The rapacious regional powers may in fact pursue a limited war, striking quickly for narrowly defined geographic objectives: their goal is not the territorial conquest of whole states but a gradual revision of the regional order, and they have demonstrated an aversion to direct and large confrontations with the United States and its alliances. To respond to this threat, it is crucial to have some frontline states armed with offensive capabilities. Through such capabilities, the targeted states can steel their own deterrent, increasing their ability to deny the enemy’s limited objectives. At the same time, they can make allied participation less costly and thus more credible, elevating the risk of the larger war the rival fears.
Defensive Mindsets, Offensive Capabilities
Before examining the strategic benefits of offensive capabilities, it is important to note frontline states such as Poland or Japan are interested in defending their independence, not in expanding their influence or control. They are status-quo powers, benefiting from the decades-old order underwritten by the United States and maintained by its system of alliances. Their mindset is defensive. The question they face concerns the most effective way of shoring up their defenses.
There are two basic ways in which exposed frontline states can defend themselves against an aggressive neighbor: they can develop a…