But Washington and its principal NATO allies now repudiate the concept of spheres of influence, contending that it has no place in the modern international system. Condoleezza Rice, George W. Bush’s Secretary of State, made that point explicitly in response to Moscow’s 2008 military intervention in Georgia. She scorned the notion of Russia’s primacy along the perimeter of the Russian Federation as the manifestation of “some archaic sphere of influence.” Secretary of State John Kerry clearly holds similar views. In November 2013, he even declared that “the era of the Monroe Doctrine is over.” Following Russia’s annexation of Crimea, Kerry asserted that “you don’t in the 21st century behave in 19th century fashion” by invading a neighbor.

That attitude is unrealistic. True, the revolution in weaponry, transportation and technology over the past century has made geography less relevant. Nations may now have vital economic ties with far‐​flung countries that exceed those with neighbors. And a distant adversary may strike with devastating force without needing to have bases or client states in the immediate region, making a great power’s security “buffer zone” far less valuable and effective. But while such developments have diminished the importance of geographic factors, they have not rendered them irrelevant. Policymakers will still regard encroachment by a potentially hostile power as a threat to national interests, and perhaps even a direct threat to national security.

Moreover, the current US attitude is more than a little hypocritical. Washington has firmly resisted Russia’s attempt to re‐​establish even a limited sphere of influence in Eastern Europe or Central Asia. Likewise, the United States has rebuffed China’s bid to establish a dominant role in the South China Sea. Yet Washington has intervened militarily as recently as the 1980s (Grenada and Panama) or even the 1990s (Haiti) within its traditional sphere of influence in the Western Hemisphere. US leaders also have looked on benignly as a key ally, France, has repeatedly intervened in its former colonial holdings in Africa.

Washington’s highly selective opposition to spheres of influence threatens to damage relations with Moscow and Beijing. Russian leaders understandably regarded NATO’s expansion into Eastern Europe as a hostile intrusion into a region that historically had been important to Russia. That was especially true of the Alliance’s incorporation of the Baltic republics, which had been part of the Soviet Union. Loose talk in Western capitals about bringing such nations as Ukraine and Georgia into NATO heightened Moscow’s apprehension. Vladimir Putin asserts that Russia’s actions in Crimea were motivated, at least in part, by the seemingly inexorable eastward expansion of a US‐​led military alliance. Although his statement may be self‐​serving, it is not entirely without merit. Vocal Western support for opponents of the pro‐​Russian government in Kiev undoubtedly made the Kremlin suspect that the United States and the European Union intended to wrench Ukraine out of Moscow’s orbit and make it a pro‐​Western client state.

Washington and its allies need to adopt a more realistic and accommodating policy. Whether Western policymakers wish to acknowledge it or not, spheres of influence still play a role in international affairs, and will continue to do so in the coming decades. It is an inherent feature of an international system in which the nation state is the principal decision‐​making unit and great powers perceive the need to protect core national interests.

Instead of attempting to defy that reality, US and European leaders should focus on getting major powers to exercise more subtlety in managing their spheres of influence. Washington’s conduct in the Western Hemisphere after President Franklin Roosevelt proclaimed the Good Neighbor policy in the 1930s, although hardly perfect, was an improvement on the crude imperial interventions that characterized the first decades of the 20th century. And it certainly stood in contrast to Moscow’s heavy‐​handed creation and maintenance of the Soviet empire in Eastern Europe.

Ironically, another Soviet policy, the relationship with Finland, may offer a worthwhile model for appropriate sphere‐​of‐​influence behavior in the 21st century. Restraints on the country’s external behavior were quite stringent, and Helsinki realized that even a limited security relationship with the West was off‐​limits. Moreover, Finland was expected to adhere to the Soviet Union’s diplomatic line in the United Nations and other international bodies. But Moscow allowed the Finns to conduct their domestic affairs with minimal interference.

That kind of behavior elsewhere on the part of Russia, China, and other major powers should be tolerable to the United States and its allies. It might not live up to idealistic aspirations regarding international behavior, but it would be a workable arrangement to minimize great power tensions. The current Western approach is doing the opposite.