Ever since Britain’s Foreign Secretary Lord Grey in 1914 declared that the arms race had made war “inevitable,” the question of whether military rivalry causes war has perplexed policymakers and scholars alike.

In 1919 the peacemakers agreed with Lord Grey.  To guarantee lasting peace, they made disarmament one of the aims of the League of Nations.  The events of the 1930s, however, appeared to prove Grey wrong.  It was not the arms race that caused another World War, but the abject failure of France, Britain and the United States to outgun Japan, Italy, and above all Hitler’s Germany.

During the Cold War, the question became politicized.  Echoing Lord Grey, peace campaigners decried the arms race as a mad rush to Armageddon and demanded détente.  Ardent Cold Warriors cautioned against relaxing the pace of competition against the Soviet Union and invoked the conventional wisdom derived from the 1930s by condemning their critics as weak-kneed appeasers.  For Cold War hawks the collapse of the Soviet Union under the burden of the arms race seemed to confirm the wisdom of racing.  Others pointed to Gorbachev’s decision to stop the arms race rather than stoking it and to loosen Russia’s grip on Eastern Europe as decisive.

In any event, the end of the Cold War took the steam out of the debate.  In the 1990s arms race studies lacked immediate relevance.  The United States, after all, was the world’s only superpower, and the Americans pioneered advanced military technologies that would stave off any challengers.  After the terrorist attacks of 9/11, the most dangerous threat became international terrorism.

As the centenary of 1914 approaches, however, the arms race question is once again relevant.  If Iran achieves nuclear capability, then its neighbors will likely follow suit.  The outlook in South Asia and Asia is worrisome.  Pakistan and India have built up their nuclear arsenals.  North Korea exploded a crude atomic device and is probably working on better ones.  Beijing is modernizing its army, air and missile forces, and expanding its navy at a pace that alarms Tokyo and Washington.  Outer space and cyberspace are now arenas for escalating competition in lethal hardware and disruptive software.  And we are on the threshold of a new race in autonomous killer robots and drones.

Will these arms races end in war?  My answer is yes, if we learn the wrong lesson from the three big arms races of the last century.  To be sure, Lord Grey’s formula was too simple:  arms races do not “inevitably” lead to war.  The Cold War is a case in point.  Underlying political conflicts cause wars and drive arms races.  But the conventional lesson derived from the 1930s is equally crude.

When Hitler came to power in 1933, he had hoped that Britain and France would stand still while Germany raced ahead in armaments.  Once he had achieved military supremacy, he intended to launch wars of expansion in central Europe and then conquer the Soviet Union.  In 1935-36, however, Britain and France reacted to German rearmament by raising their armed strength.  British and French statesmen hoped to arm just enough to deter Hitler and to force him to negotiate.  Hitler’s bid for military supremacy and British and French efforts to deter him both failed for the same reason:  the arms race.

Arms races are dynamic.  Arming incites counter-arming, and the cycle continues until a political deal is reached or one side gives up the competition.  By 1937 Europe was locked into an armaments spiral.  In London and Paris politicians wondered when Hitler would understand that he could not win the arms race while their military chiefs lobbied for more resources.  In Berlin Hitler slowly began to realize what his economic and military advisors told him was correct—Germany could achieve security but not win military supremacy.

In the summer of 1938, frustrated by the thought that he was losing the arms race, Hitler threatened Czechoslovakia.  His generals told him that he could not conquer the Czechs without provoking war against Britain, France and possibly the Soviet Union, a war that Germany could not win.  Britain’s Prime Minister Neville Chamberlain flew three times to Germany to discuss a peaceful resolution.  He hoped that by negotiating with Hitler, he could halt the arms race by addressing the political grievances propelling it.  Ironically, Chamberlain’s achievement, the notorious Munich agreement of September 1938, only accelerated the race.  After Munich, it soon became clear that nothing had changed:  France, Britain, Italy, the United States and the Soviet Union all sped up their arms programs.

In 1939 Hitler accepted that the arms race and thus time had turned against him.  Germany had made enormous strides, but its rivals had greater resources and more slack in their economies to make armaments.  Yet, Hitler refused to be deterred.  Unable to reverse the self-defeating consequences of the arms race, he decided to risk an all-out war in Europe by attacking Poland.

Winning an arms race is not a guarantee of peace.  In the future, national leaders in the world’s hotspots may decide that it is better to attack early than to accept ever-greater military inferiority.  Yet, in a world where force plays a vital role, the grim truth is that not racing is as hazardous as racing.  The safest bet is to persuade everyone that that the race is not worth running at all.