Hal Brands
An American war against China or Russia would be truly awful. Even if the United States won — no sure thing — it could well suffer costs and casualties that would make the toll of the Iraq and Afghanistan wars seem minor by comparison. So is there a way the US could stymie a Chinese attack in the Pacific, or a Russian land-grab in Eastern Europe, without having to defeat enemy forces head-on? This is the motivating question behind the idea of “horizontal escalation.”
Horizontal escalation is a strategic concept that relies on attacking an adversary’s weaknesses outside the theater where the fighting started, so as to avoid confronting its strengths within that theater. It is an alluring idea that has won support from some key national security professionals. Unfortunately, it probably won’t work.
Horizontal escalation is a response to a genuinely difficult problem: the immense challenges associated with directly defeating Chinese or Russian aggression.
As studies by the Rand Corp. have shown, if Beijing decides to use force against Taiwan, or Russia assaults its Baltic neighbors, the US would be hard-pressed to respond effectively. American forces would be defending exposed territories on the adversary’s doorstep. They would have to project decisive power over thousands of kilometers, into areas where China and Russia can bring to bear formidable “anti-access/area denial” capabilities (sophisticated air defenses, anti-ship missiles and others). It would be harder than anything the US military has done since World War II.
It is because these scenarios seem so ghastly that horizontal escalation looks so attractive. For years, US strategists have argued that Washington should respond to Chinese aggression in the Western Pacific with a maritime blockade that would starve China of oil and other critical imports. Similarly, the US and its allies could punish an aggressive Russia by leveling harsh financial sanctions, such as kicking Moscow out of the Swift global payments system. In theory, the US military could even conduct operations in secondary theaters — targeting Russian forces in Syria, for example — as a way of distracting and punishing the enemy.
Rather than confronting China and Russia where the fighting would be toughest, the thinking goes, the US would broaden the conflict into areas where it has the advantage, eventually inflicting enough pain that the enemy yields.
The theory of horizontal escalation thus holds that the US can wage a war on its terms rather than the enemy’s — and that it can achieve victory without paying the price of a more direct approach. Unfortunately, this theory is too good to be true: Horizontal escalation ultimately stumbles on several key problems.
Financial sanctions or a far-seas blockade can inflict real pain, but probably not enough to persuade Chinese rulers to sign their own political death warrants. And both China and Russia are steadily working to make themselves less vulnerable to this sort of pressure: Russia by encouraging its oligarchs to bring their assets home so they are less vulnerable to Western sanctions, and China by building overland supply routes that are less vulnerable to American naval power.
The US might still find some forms of horizontal escalation useful in a major conflict with China or Russia, as a way of complementing rather than substituting for a more direct response. But its weaknesses as a standalone concept are such that for America to defend its interests in Europe and the Western Pacific it must be able to prevent Russia and China from conducting successful aggression in the first place.
As both the National Defense Strategy and the National Defense Strategy Commission have made clear, this will not be easy. It will require pushing allies and partners to develop their own anti-access/area denial capabilities, as opposed to the more expensive but less useful planes and large naval vessels that the Taiwanese, among others, seem to love. It will entail investing in new technologies that allow the US to project power even in contested environments, and developing the new operational concepts that will enable American forces to use those capabilities most effectively. And it will involve making smart upgrades in America’s nuclear arsenal, to ensure that an adversary does not try to escalate itself out of conflict.
All these changes are only beginning, as some former Pentagon officials have acknowledged, and completing them will present a strenuous test of whether the US can meet the challenges of deterrence and defense in the 21st century. But given the shortcomings of horizontal escalation, tackling those broader challenges squarely is still the best approach.
Hal Brands is a professor at Johns Hopkins University’s School of Advanced International Studies.