“What would America fight for?” screams the cover of this week’s Economist. The “cumulative message” of America’s unwillingness to bring its might to bear on Syria or Ukraine, “is weakness.” Mr. Obama has “broken the cardinal rule of superpower deterrence: you must keep your word.” Apparently, credibility is “easily lost and hard to rebuild.” There is a “widespread impression in the Middle East” that “the lion has turned into a pussycat,” continues the main article. In Asia, allies “doubt that America would risk a shooting war” with China, and are arming themselves. Even Japan is “not sure” about America’s protection.
Is this how deterrence works? How do states calculate the credibility of their allies and adversaries? Does inaction in Syria and Ukraine risk undermining America’s credibility in Europe, Asia, and the Persian Gulf? In this essay I will argue that the Economist is absolutely wrong. This is not how credibility works. America’s unwillingness to use force in Syria or Ukraine tells us nothing about the credibility of America’s commitment to defend its key allies.
For deterrence to hold, the defender must convince the attacker not only that he has the military wherewithal to defend an ally or territory, but also that it is in his interest to do so. If the attacker has a significant interest at stake, a weak defender cannot deter him from attacking. Even a strong defender does not enjoy much credibility if he has little at stake in the outcome. Explicit commitments, even treaty alliances, are cheap talk. A commitment to defend an ally is only credible if the defender truly prefers to fight rather than concede. For a world power with protectorates all over the globe, the credibility of extended deterrence (deterring aggression against an ally not the homeland) is directly tied to the importance of the protectorate in the balance of power.
The above paragraph explicates the logic of what Daryl G. Press, in his seminal book Calculating Credibility, calls the “Current Calculus” theory of credibility,
which argues that decisionmakers evaluate the credibility of an adversary’s threats by assessing (1) the balance of power and (2) the interests at stake in a given crisis. If an adversary issues a threat that it has the power to carry out, and an interest in doing so, the threat will be believed, even if that country has bluffed in the past. But if it makes a threat that it lacks the power to carry out, or has no interest in doing so, the credibility of that threat will be viewed with great skepticism.
He tests this against “Past Actions” theory which “holds that credibility depends on one’s record for keeping or breaking commitments.” Evaluating the way Germans assessed credibility during the 1930s, the British assessed credibility in the 1950s, and the United States assessed credibility in the 1950s and 1960s, Press finds that
In each case credibility was primarily determined by the balance of power and the level of interests at stake, just as Current Calculus theory predicts. Past Actions theory, in stark contrast, badly fails an embarrassingly easy set of tests.
In other words, The Economist’s “cardinal rule of superpower deterrence: you must keep your word” is simply wrong. The answer to the question – what would America fight for? – matters greatly. However, the answer must be sought not in American inaction in irrelevant regions, but in the global balance of power and US interests. The next article in the section correctly assesses that American military power is unrivaled. That is, the world is still unambiguously unipolar. To put it bluntly, no other power has the wherewithal to put up a fight with the United States. Therefore, the question can be answered simply by analyzing US interests. (Such an exercise is much more complicated in a multi-polar system.)
Being the strongest state by a margin means that no state in the international system can threaten the United States. The United States would be nuts to not want to prolong unipolarity as long as possible. This is official: the United States is determined to prevent the emergence of a peer competitor. US grand-strategy is straightforward. There are only three regions in the world with enough war potential to produce a great power that can compete with the US: North America, Europe, and East Asia. This is simply because 80% of the world’s landmass and 90% of the world’s population is in the northern hemisphere. Put this together with the fact that the tropical zone is hostile to human exploitation (being mostly either desert or impenetrable rainforest), we can easily see why all the great powers of the modern era have hailed from the northern temperate zone.
If a state were to become the regional hegemon of Europe or East Asia, it would command at least as much war-making capability as the United States. Moreover, a regional hegemon would, like the US in the Western Hemisphere, be free to meddle in others’ backyards. Therefore, it is an enduring strategic interest of the United States that no state attain regional hegemony in either of these two regions. After emerging as a great power in 1898, the United States has weighed in the Eurasian balance thrice, each time to prevent another power from becoming a regional hegemon. The US fought in World War I despite tremendous opposition at home to prevent German mastery over Europe; it went to war against Imperial Japan to prevent it from becoming the regional hegemon in East Asia; and it moved in to contain the Soviet threat at the end of World War II, not leaving till the Soviet Union collapsed nearly five decades later.
The Persian Gulf has played a key role in US grand-strategy since the interwar period. Once militaries came to depend on oil, energy security became a strategic interest of all great powers. The continental-sized powers – US and Russia – had large supplies of their own. Germany and Japan, on the other hand, were dependent on external supplies. This is why Hitler made a concerted effort to reach Baku, then the world’s biggest oil field. This is also why Japan attacked Pearl Harbor. (Since it was so critically dependent on external supplies, the US economic blockade was crippling. Moreover, even if Japan took over the oil-rich Dutch East Indies, it could’ve been cut-off at any time by US naval squadrons based in Guam). Military preponderance over the Persian Gulf has allowed the United States to exercise a veto over these two powers. China is now in the same boat, dependent on West Asian energy and exposed to US strangulation.
The other core strategic interest of the United States is to maintain itself as the only great power in the Western Hemisphere. North America is, of course, the US’ near abroad. This means that Canada and Mexico cannot conduct independent foreign policies. Moreover, the security of sea-lines of inter-coastal communication in the United States require preponderance over Central America, “our little region over here that never bothered anyone.” Furthermore, maritime strategy requires that the US maintain a secure perimeter around the Western Hemisphere. Hemispheric defense, considered and rejected as being not ambitious enough in 1942, is, and will remain, the ultimate backup plan for American security.
What happens in other landmasses cannot upset the global balance of power in any significant way, and therefore does not threaten US’ position on the world stage. To read too much into US policies with regard to small states in the Levant and in Russia’s near abroad is folly.
This does not mean that US credibility in Asia is secure. Indeed, it is very clear that the question in the Taiwan Strait and the Korean Peninsula is not whether extended deterrence is likely to hold, but for how long. In China, the United States faces its strongest rival in history. It is an open question when and whether China will become stronger than the US. What is clear is that China will eventually become strong enough to dominate its immediate vicinity. At some point, the United States will not be able to deter China from reabsorbing Taiwan or bringing the Korean Peninsula in its sphere of influence. For now, the US is strong enough to protect both Taiwan and South Korea. But for how long this continues to be the case depends on the rapidity of China’s rise.
Japan, located on the flank of the continent (a mirror image of Britain), is the gate-keeper of Asia. The US cannot bring any power to bear in the region without controlling or allying with the Japanese. Not only does Japan occupy the most important geostrategic location in East Asia, it is also a great power in its own right; one that can contribute significantly towards containing China. Japan can rest assured. America has its back. The same can be said of the European Union. There is simply too much war potential to be conceded. The renewal of the threat from Russia has served as a shot in the arm for Nato.
US strategic interests are not restricted to these four landmasses. Even more important, especially if a potential regional hegemon rears its head in either extremity of Eurasia, is maintaining US’ command of the global commons: unassailable military dominance over the sea, air, and space. US primacy in space requires maintaining a technological lead over the lesser powers. Air-Sea mastery requires a globe-spanning logistic network of bases and control of sea lines of communication. The control of these sea lanes requires maintaining exclusive military access to key choke points; what First Lord of the Sea Admiral Fisher called the “five keys that lock up the world”: Singapore, Hormuz, Suez (and Bal-el-Mandeb at the other mouth of the Red Sea), Gibraltar, Dover, and the Panama Canal. Control over these (and a handful of others like the Turkish and Danish Straits, and the Cape of Good Hope) ensures US naval mastery, allowing it to guarantee the free-flow of energy and commerce throughout the global economy. For instance, Singapore can rest assured. The US would protect it unless it is surrendering the Indian Ocean along with the Western Pacific. [When Great Britain surrendered global naval primacy in 1900, it withdrew its effective “naval perimeter” to between Singapore and Bermuda.]
This completes the list of vital strategic interests of the United States. When any of the above vital strategic interests of the United States is at stake, only a fool would doubt US credibility. Notice what is not in it. Israel’s security is a ‘concern,’ not a vital interest. While protecting the oil monarchies is a vital interest, preventing Iran from acquiring a nuclear deterrent is not one. A nuclear Iran would make dominating it a little bit harder but the US would still be able to blockade and contain Iran at will. A nuclear deterrent will only buy Iran security against an outright invasion. Maintaining international norms against the use of chemical weapons is also a concern. As is maintaining whatever norms The Economist imagines exist against the use of force in world affairs.