Revisionist powers are on the move. From eastern Ukraine and the Persian Gulf to the South China Sea, large rivals of the United States are modernizing their military forces, grabbing strategic real estate, and threatening vulnerable U.S. allies. Their goal is not just to assert hegemony over their neighborhoods but to rearrange the global security order as we have known it since the end of the Second World War.
We first wrote about these emerging dynamics in 2010, and then in TAI in 2011. We argued three things. First, that revisionist powers were using a strategy of “probing”: a combination of assertive diplomacy and small but bold military actions to test the outer reaches of American power and in particular the resilience of frontier allies. Second, we argued that the small, exposed allies who were the targets of these probes were likely to respond by developing back-up options to U.S. security guarantees, whether through military self-help or accommodation. And third, we argued that that China and Russia were learning from one another’s probes in their respective regions, and that allies themselves were drawing conclusions about U.S. deterrence in their own neighborhood from how America handled similarly situated allies elsewhere.
Five years later, as we argue in a new book released this month, these dynamics have intensified dramatically. Revisionist powers are indeed probing the United States, but their methods have become bolder, more violent—and successful. Allies have grown more alert to this pressure, amid the steady whittling away of neighboring buffer zones, and have begun to pursue an array of self-help schemes ranging from arms build-ups to flirtations with the nearby revisionist power. It has become harder for the United States to isolate security crises to one region: Russia’s land-grabs in Eastern Europe provide both a model and distraction effect for China to accelerate its maritime claims in the South China Sea; Poland’s quest for U.S. strategic reassurance unnerves and spurs allies in the Persian Gulf and Western Pacific.
By degrees, the world is entering the path to war. Not since the 1980s have the conditions been riper for a major international military crisis. Not since the 1930s has the world witnessed the emergence of multiple large, predatory states determined to revise the global order to their advantage—if necessary by force. At a minimum, the United States in coming years could face the pressure of managing several deteriorating regional security spirals; at a maximum, it could be confronted with a Great Power war against one, and possibly two or even three, nuclear-armed peer competitors. In either case, the U.S. military could face these scenarios without either the presumption of technological overmatch or favorable force ratios that it has enjoyed against its rivals for the past several decades.
How should the United States respond to these dynamics? As our rivals grow more aggressive and our military edge narrows, we must look to…