Thucydides’ purpose in his great epic was to account for “what led to this great war falling upon the Hellenes.” He acknowledged that what we know as the Peloponnesian War was produced by many different disputes and depicted them masterfully, laying bare their specificities. But, in the opening pages, he warns us that dwelling on the particulars obscures “the real reason” for carnage that ruined Hellas. “What made war inevitable,” he tells us early on in his masterpiece, “was the growth of Athenian power and the fear it caused in Sparta.” He might have added, for his account makes it abundantly clear that such was the case, “and in Sparta’s closest allies as well.” Among the lessons offered by Thucydides is that we ought not to dwell on the trees and risk missing the lines of the forest—the larger trends that drive politics and war.

Thucydides’ epic has inspired many explorations of what in international-relations scholarship is referred to as “power transitions.” Not a few of these studies conclude that these mega-shifts are among the most perilous periods in the politics among nations. Why? Because the established, dominant power fears that, even if it is has not yet been surpassed and may not be anytime soon, the margin of its advantage over an ascendant rival, which it has long watched uneasily, is diminishing—and will likely continue to do so. The rising power, having lived under a political-military-cultural-institutional order that reflects the preponderance of the reigning hegemon, and that therefore protects and advances its interests, grows in confidence. Eager to demonstrate to itself and others that a new era is nigh, it begins to probe and to push so as to assay the reaction and explore the possibilities.

Shifting circumstances and the attendant uncertainty make power transitions hazardous. The leaders of the dominant power whose position is being eroded feel that they must show that their side is still supreme. That impulse arises from the need to retain legitimacy among their citizenry and to show the challenger that they still have plenty of power and resolve and should not be underestimated. The leaders of the ascendant rival, on the other hand, are no less eager to show their own people, the hegemon, and the latter’s allies, that a new arithmetic of power is emerging. One side’s fear and the other side’s hubris produce a volatile mix. The result need not be, as it was in Hellas, a catastrophic war. A shifting balance of power could instead create a more benign context, though one conducive to apprehension, limit-testing, crises, misperceptions, and strategic reassessments prompted by uncertainty and fear.

The latter denouement is worth keeping in mind when one assays the origin and significance of recent events involving the assertion of China’s power in East Asia. One of these was Beijing’s proclamation on November 23 of an Air Defense Identification Zone (ADIZ) extending into the East China Sea and covering islands that Japan and South Korea control but that China claims. An ADIZ is standard practice and thus hardly an illegal or belligerent act, but China’s version is more stringent than is customary. It requires aircraft passing through to file flight plans with the Chinese authorities and to be under the guidance of Chinese air-traffic controllers, even if the plane is not heading to China. Moreover, it overlaps with Japan’s ADIZ, covering the Senkaku/Diaoyu islands, which both China and Japan claim.

The United States, followed by Japan and South Korea, flew military aircraft through the Chinese ADIZ to demonstrate that they didn’t accept its legitimacy; but various commercial airlines (Singapore Airlines, Qantas, Korean Airlines, Asiana Airlines and American air carriers, as per an FAA directive), in an understandable decision designed to ensure their passengers’ safety, agreed to comply with China’s stipulations. South Korea subsequently expanded its ADIZ, extending it into China’s, to underscore Seoul’s claim to (and control of) the Ieodo (Suyan Rock in Chinese parlance), which is disputed by Beijing. Yet these defiant gestures by Washington, Tokyo, and Seoul do not change the reality that has emerged, which is that China’s action, taken from a position of unprecedented confidence and capacity stands. The question is whether Beijing will follow up with an expansive ADIZ to back its claims in the South China Sea.

The ADIZ decision is but one example of China’s determination to stake its maritime claims. As far back as 1974, it defeated Vietnamese forces, taking control of those parts of Paracel/Xisha archipelago that it did not occupy already. More recently, China has continually dispatched naval patrols into the waters surrounding the Senkaku/Diaoyu islands and staged naval exercises in nearby waters, prompting Japan to follow suit. Beijing has also taken a tough line on the Spratly/Nansha Islands, asserting its legitimate ownership, rejecting the competing claims of Taiwan, Vietnam, and various other Southeast Asian states, combining tough rhetoric and actions (patrols in disputed waters, surveillance), notably against the Philippines over Huanyang Island/Panatag (Scarborough) Shoal, but not just there.

That the disputes over these various island groupings—many of them uninhabited rocks—in several instances pits China against allies of the United States or countries with longstanding and close ties to Washington hasn’t deterred Beijing. To reassure its partners, the United States has dispatched diplomatic luminaries, issues statements of solidarity, and conducted naval exercises with some of China’s coclaimants. None of these steps has made Beijing any less hesitant to assert its claims. Its uncompromising stance has created doubts in the region about whether American protection is now worth what it once was. The standard explanation of what motivates China in the quarrels over these islands and their surrounding waters invokes the importance of sea lanes essential to Northeast Asia’s trade and defense and bountiful offshore oil and gas deposits. While scarcely irrelevant, these considerations don’t explain why China has been acting with particular assurance in recent years, the latest example of which occurred on December 5, when a Chinese naval vessel and an American warship nearly collided when the former crossed in front of the latter at close quarters in the South China Sea.

The islands’ economic and strategic value is not new. What’s different is that China now wields unprecedented economic and military power, thanks to the breakneck pace of its economic growth and technological modernization since 1978, its purchases of an array of manner of advanced Russian armaments, and its progress in across-the-board military modernization. China has long been determination to erase the humiliation it endured with the onset of nineteenth century. Having been a center of cultural splendor and wealth for centuries, it became a plaything of the Western imperial powers and of Japan, enduring more than a century of exploitation, coercion, humiliation and occupation. The memories of this dark period are ensconced in the minds of Chinese, both rulers and the ruled. Part of Beijing’s swagger in East Asia stems from the determination to bury this painful past and to ensure that it never repeats itself. That enterprise necessarily entails challenging Washington’s long-held primacy in region. It’s not, therefore, just about energy, strategic outposts, waterways and other such tangibles. It’s as much, if not more so, about casting off the burdens and demons of the past.

This helps explain why nationalism has sidelined Marxism/Maoism as Beijing’s legitimating ideology. The latter has little to offer when it comes to the managing and modernization of a twenty-first century economy, and may even be an impediment. Besides, for the well educated, tech-savvy, and materialistic members of Chinese middle class and intelligentsia, especially the younger individuals among them, regaining respect and righting wrongs has a resonance that chiliastic programs devoted to revolutionary transformations and utopia simply lack. The Mao suit is now a sartorial curiosity, the Red Book a dusty relic, another victim of the Internet’s richer offerings. If there’s one group that’s more nationalistic than the Chinese leadership, it’s China’s educated young urbanites, who take to chat rooms and websites to issue denunciations and demands for toughness whenever China’s pride is injured.

There are two trends that bear on China’s role in the world and that therefore have consequences for America and its allies and friends. The first is that, over the past two decades in particular, China has raised the risks that Washington will have to assume to protect, or even reassure, states that have relied on preponderant American power for protection. Russian arms sales to China, which cover just about every category (including surface ships, submarines, fighter jets, air defense and anti-ship missiles, surveillance and fire control radars, and helicopters) and have amounted to $31 billion between 1992-2012. They have played a pivotal part bringing about this change, and the projected sale of the Su-35 multirole fighter will extend Beijing’s capacity to patrol the vast South China Sea and to project power with greater effect. Washington’s allies and friends still believe that America can be relied upon to defend them in an-all out war with China. But when it comes to skirmishes, the controlled application of force, and displays of power designed to intimidate, the value of the American connection as a counterbalance to China is diminishing. States in the region understand that the United States will risk confronting China only under exceptional circumstances and so the cumulative effect of carefully calibrated displays of strength, and the accompanying disregard for American power, will inevitably have psychological repercussion across East Asia that work to China’s advantage.