The vast destruction wrought by the atomic bombing of Japan in August 1945 should have been enough to convince national governments that the game of war was over.

Wars have had a long run among rival territories and, later, nations, with fierce conflicts between Athens and Sparta, Rome and Carthage, Spain and Britain, and the combatants of World Wars I and II among the best-known. Although the wars had a variety of causes and were sometimes promoted with lofty ideals and slogans, they were often occasioned by disputes over territory and resources. Not surprisingly, the most powerful, most heavily-armed countries, which had the best chances of emerging victorious in a military conflict, were usually the most eager for it.

With the advent of nuclear weapons, however, the traditional pattern of great power conflict—regarding other nations as enemies, confronting them militarily, and waging devastating wars against them—had acquired a ghostly quality.  As Albert Einstein remarked:  "General annihilation beckons."

Unfortunately, the governments of the great powers were slow to learn this lesson. Despite their professed support for international security under the leadership of the United Nations, they expanded their military budgets and engaged in new military invasions and wars. Meanwhile, they built vast nuclear armadas to prepare for future armed conflicts.

Today, the great power war game is particularly evident in Ukraine, where nuclear-armed nations are engaged in a tense standoff.  Russia, which seized portions of eastern Ukraine in 2014, has massed 100,000 troops, plus missiles, tanks, and warships, on the borders of that nation. And, although the Russian government has denied any intention to invade, its military juggernaut has clearly not been assembled to play potsy. Indeed, President Vladimir Putin has issued ultimatums demanding that NATO reject membership for Ukraine and remove military forces from NATO nations in much of Eastern Europe.

Although dismissing any intention of sending troops to Ukraine, the U.S. government, along with its NATO partners, has been dispatching defensive weapons to the Ukrainian government and threatening a “severe” response to a Russian invasion. The U.S. government maintains that it is merely trying to avert Russia’s invasion or takeover of a weaker neighbor. But the Ukraine confrontation might have been avoided had previous U.S. administrations not incensed Russia’s rulers by blithely expanding NATO eastward—right up to Russia’s border.

It's certainly an explosive situation, as well as an exceptionally dangerous one, particularly given the fact that Russia and the United States each possess about 6,000 nuclear weapons.