John Bolton speaks at the Republican Jewish Coalition in Las Vegas in March 2014. President Trump has named Bolton to be his national security adviser. (Julie Jacobson/AP)

Last week, when President Trump announced he was replacing H.R. McMaster with John Bolton as his new national security adviser, some foreign policy hawks rejoiced. However, most analysts worried, given Bolton’s militant rhetoric and hawkish positions — attitudes that worried even other Republicans during the George W. Bush administration.

Focusing on Bolton individually means we miss a larger and more troubling point about how the United States has conducted foreign policy since the end of the Cold War. In an age of overwhelming U.S. military dominance, there is no other country to push back when the United States gets aggressive. As a result, militant and assertive views have more scope to shape policy.

Without international pushback, American leaders can follow their own instincts, limited only by domestic attitudes. For the three reasons below, that could lead to war.

1. U.S. power has a troubling side.

Since the end of the Cold War, the United States been incredibly secure, with a robust nuclear arsenal, large ocean moats and — above all — no peer competitor. This has helped the United States in many ways. At the same time, the United States has had an exceptionally activist foreign policy — while largely evading meaningful international consequences for its behavior.

Despite international opposition, for instance, no countries aligned against the United States or retaliated for its interventions in Iraq, Libya or Syria, all of which were partners of major nations like Russia and China. In the 1990s and early 2000s, Russia complained about NATO expansion into the Soviet Union’s former sphere of influence but largely cooperated with the West — at least, until 2014. Over the last decade, the United States has begun to risk war for states like Japan and the Philippines by backing their contested maritime claims in East Asia.

Of course, U.S. actions often led to human suffering in other countries, harmed many U.S. service members and exacted a toll on the U.S. economy. These consequences pale in comparison with the costs of tangling with another major power. Because the United States is more powerful and secure than any other country in modern history, it can often do what it wants with comparatively few direct costs.

Bolton’s appointment reflects this. Trump can consider his militant ideas partly because there is no obvious penalty for adopting hawkish policies. Consider the counterfactual: If the Soviet Union was around to retaliate for a U.S. strike on Iran or North Korea — or if Iran or North Korea were great powers themselves — Trump would probably not want an adviser who has argued for war. The consequences would just be too costly.

2. Unchallenged U.S. dominance means individual leaders have enormous influence on foreign policy.

Because the United States is secure and powerful, its foreign policy since 1991 has turned in large part on what leaders want and what domestic politics lets them get away with. Of course, leadership mattered at other points in U.S. history, too: The transition from John F. Kennedy to Lyndon Johnson and Richard Nixon, for instance, affected the course of the U.S. war in Vietnam. Still, overwhelming U.S. power since the Cold War means individuals and domestic politics are especially influential.

For example, individual leaders and domestic politics influenced whether the United States intervened in civil conflicts in Somalia, Bosnia, Kosovo, and Libya. Likewise, the decision to expand NATO depended heavily on individuals and personal attitudes in the Clinton administration. Meanwhile, it is easy to imagine, say, a President Al Gore might have made different decisions than did President George W. Bush after 9/11 about toppling the Afghan and Iraqi governments in 2001 and 2003, and then about subsequently engaging or disengaging from reconstruction efforts.

Analysts can certainly debate whether any one of these policies was right or wrong. The point remains that individual policymakers did not have to think much — beyond what they deemed appropriate — about what the rest of the world might think or do. Being the dominant nation means no external force pushes back to shape U.S. behavior.

All this means sage leadership that screens policy ideas is especially important. With an inexperienced leader like Trump in the Oval Office, Bolton’s views can gain traction partly because America still reigns as the sole superpower.

3. Bolton’s appointment is a reminder that countries play to their strengths.

While it is true the United States is the world’s dominant power, U.S. supremacy is not absolute. The United States is facing a rising China, the prospective rise of countries such as India and Brazil and a variety of challenges from Russia. Over the last two decades, these nations have cut into the United States’ economic lead, just as their political and diplomatic influence has grown.

The United States continues to have an unchallenged military advantage. No other country can match the U.S. ability to project power across great distances. Bolton’s ascension may reflect this. Policymakers focus on the use of force because that is where the United States outcompetes the rest of the world.

This should not be surprising. Declining great powers often consider force against adversaries — and sometimes use it — to compensate for relative weaknesses in other areas of statecraft. Germany, for instance, pushed for war with an economically rising Russia before 1914. Similarly, U.S. strategists in the 1960s considered a preventive strike against China before the People’s Republic acquired nuclear weapons.

Seen in this light, Bolton’s appointment is doubly worrisome. Not only may he be inclined to hawkish positions because force is relatively cheap and easy for the United States to employ, but others in the government may want to embrace his views if other foreign policy tools seem increasingly ineffectual.

With U.S. power dominant but waning, Bolton’s elevation reminds us there are few limits to — and some momentum behind — a militaristic U.S. foreign policy.

Joshua R. Itzkowitz Shifrinson is an assistant professor of international affairs with the Bush School of Government at Texas A&M University. His first book, “Rising Titans, Falling Giants: How Great Powers Exploit Power Shifts” is being published by Cornell University Press later this year.