Finally, in early 2011, Hillary Clinton, the U.S. secretary of state, publicly endorsed peace talks for the first time. In January 2012, the Taliban agreed to open a liaison office in Qatar. But shortly afterward, the Taliban suspended discussions, describing the United States as “shaky, erratic, and vague.”

In the era of alien warfare, negotiators sit across a vast sea of cultural difference. After 1945, America’s enemies usually exhibited a Communist or Islamist worldview. By contrast, U.S. negotiators saw issues through the lens of a democratic and rights-based society. One recent survey asked foreign officials to describe the American negotiating style. Officials from very different countries consistently gave the same answers, depicting U.S. diplomacy as a combination of businesslike pragmatism, a lawyerly concern with precise commitments, a superpower’s tendency to impose terms and a moralistic style—along with an American penchant for using incomprehensible sports terminology like “slam dunk.”

Culture shapes all sides’ core assumptions about the conflict, communication style and perceptions of the adversary. Ignorance is sometimes bliss. During the Korean War peace talks, for example, Communist envoys referred to the U.S. negotiators as “dog food”—a vicious insult in East Asia that fortunately passed over the heads of the Americans.

More often, however, alien warfare proved a major impediment to effective negotiation. Each side saw the other as ruthless, sanctimonious and doctrinaire. General Matthew Ridgway described the Communists in Korea as “treacherous savages.” On one occasion, the opposing negotiators in Korea sat in silence for over two hours. During this time, the North Koreans exchanged notes among themselves—containing insults about the Americans and South Koreans in large, visible letters.

One French observer described the negotiations in Paris to end the Vietnam War as a “dialogue de sourds” or a “dialogue of the deaf.” Hanoi spent much of the time lecturing Americans about imperialism while avoiding any substantive discussions. Henry Kissinger called his opponents “tawdry, filthy shits.”

In Afghanistan, a chasm exists between American political ideals and the Taliban’s belief system, which favors sharia law and an Islamic Emirate of Afghanistan. Today, many Americans see the Taliban as a faithless enemy and any prospective deal as an illusion.

Negotiating peace is particularly challenging during a civil war. Most internal conflicts end in a decisive victory for one side rather than a peace treaty. When two countries stop fighting, their armies can pull back to recognized borders. But after resolving a civil war, the combatants are often supposed to live and even govern together. Why would the rebels give up their guns if they fear the regime will renege on any deal? Even the basic logistics of talking to insurgents are difficult. The enemy may not speak English. It may not have a home address. And its envoy could be a suicide bomber.

It is also more difficult to reconcile with opponents after an alien war. Of course, reconciliation is not always an appropriate goal—especially if the adversary is truly extreme like Al Qaeda. But with most enemies, a modus vivendi or even a durable peace is possible. After all, every single U.S. opponent in a major war from 1812 to 1945 is now an American ally: Britain, Mexico, the Confederacy, Spain, the Philippines, Italy, Germany and Japan.

Rapprochement with culturally dissimilar opponents after 1945 has been a far more challenging proposition. After the United States fought China in Korea, it took over a quarter of a century to normalize relations with Beijing. Washington was slow to recognize the Sino-Soviet split that emerged in the late 1950s and early 1960s, and continued to believe in the theory of monolithic Communism. Finally, in 1979, the two sides established diplomatic relations. Chinese premier Deng Xiaoping arrived in the United States on a goodwill visit and famously donned a Stetson hat at a rodeo—symbolically bridging the cultural gulf.

Reconciliation after the Vietnam War was a similarly tough road. The United States and Vietnam share a core national interest in checking a rising China. Flush with victory, however, Hanoi bungled the process of rapprochement by demanding billions of dollars from the United States in “reparations.” Meanwhile, Washington resisted détente by helping to propagate the myth that Vietnam was secretly holding American prisoners of war. Finally, in 1995, with the support of Vietnam veterans like John Kerry and John McCain, President Bill Clinton established diplomatic relations with Hanoi.

Rapprochement with China and Vietnam was relatively straightforward compared to the challenges of reconciling with North Korea. Even sixty years after the Korean War, there has never been a peace treaty, and the United States has yet to grant full diplomatic recognition to Pyongyang.

Peacemaking involves the creation of new narratives that emphasize common bonds. This task is much easier when the former enemies share mutual values. After the War of 1812, for example, Britain and the United States highlighted the broader Anglo-Saxon English-speaking family. But cultural overlap is missing with alien adversaries. No American enemy since 1945 aspires to copy Western humanism and democracy. What shared values exist between the United States and the Taliban?

ARE AMERICA’S future wars destined to become even more alien? The answer is probably no. For the United States, alien warfare may have peaked.

First of all, the tide of U.S. interventionism is likely to ebb. In one sense, there is nowhere to go but down. Trying to mold the clay of Afghan society represents the most alien military endeavor imaginable. How can the United States match this kind of ambitious project?

Furthermore, in the coming years, Washington will probably avoid sustained nation building in distant lands. Negative memories of the wars in Iraq and Afghanistan have triggered an “Iraqistan syndrome”—a popular aversion toward prolonged stabilization missions. In addition, the shift to a multipolar international system, with the rise of China, India and other countries, could introduce new international checks that temper American adventurism.

Warfare will also become less alien because of greater information flows about foreign countries. Globalization, communicational change and technological innovation provide new sources of knowledge about international allies and opponents. We live in the Age of Information: a time of NSA snooping, Wikileaks and Facebook. In 2002, there were about five exabytes of data online. Today, this amount of data is created every two days. As a result, Americans will probably know more about Afghan society in 2030 than in 2000.

But this raises a puzzle. The spread of information did not begin with the Internet. Technological and communicational change has heightened the flow of knowledge about foreign societies for centuries. Americans had far more data available about Afghanistan in 2001 than they did in 1901—when they might have struggled to even locate the road to Kabul.

If Americans grew steadily more knowledgeable about foreign countries, why did U.S. wars become increasingly alien experiences? The answer is that American interventionism expanded more rapidly than the flow of information. In other words, the last two centuries saw a race between globalism and globalization—and the decisive winner was globalism. American GIs leapt into distant conflicts more quickly than information flows could narrow the gulf of ignorance.

American interventionism is now likely to pause for breath—allowing information flows to catch up. If Washington displays more restraint, the spread of knowledge will make conflict less alien. All else held equal, greater awareness of adversaries should produce more effective military and diplomatic strategies. But the ebbing of alien warfare is unlikely to herald a return to the glory days of military victory. For one thing, conflict will likely remain dominated by civil wars, where Washington often struggles on the battlefield, rather than interstate wars, where the United States usually wins decisively.

In addition, communicational and technological change may have other effects that serve to help U.S. opponents. For example, globalization provides guerrillas with new opportunities to transmit their messages to foreign audiences and win external support—which is vital for the success of an insurgency. Meanwhile, the spread of information could itself spur a revival of American interventionism. Global news coverage and the profusion of social media make it more difficult to ignore conflicts on the far side of the globe. Therefore, the pendulum may swing back and Americans could adopt a more bellicose posture, triggering renewed alien warfare.

AMERICAN MILITARY history is the story of the rise of alien warfare. Over time, U.S. campaigns occurred in more distant lands, adversaries and allies became more culturally dissimilar, and conflicts evolved from interstate war to counterinsurgency, requiring greater engagement with foreign populations. Today, as the United States battles the Islamic State, there are signs of a new alien war, with Americans unable to even agree on the enemy’s name. In this increasingly unknown military environment, Washington has struggled both to wage war and to make peace.

The solution may seem obvious: less war and less nation building. And indeed, Washington should set a higher bar before using force. Two of America’s alien wars—Vietnam and Iraq—should never have been fought. Given America’s recent experiences, we should rarely, if ever, willingly start a major counterinsurgency campaign.