One of the consequences of U.S. nuclear negotiations with Iran has been increased tensions with U.S. allies in the region. Most dramatically, Saudi Arabia has signaled its displeasure at U.S. diplomacy with its Iranian rival by threatening to procure nuclear weapons from Pakistan.

Over the years, Washington’s strategy has been to reassure Saudi Arabia; for instance, in 2009, Secretary of State Hillary Clinton promised that if Iran acquired nuclear weapons, the U.S. would shield Saudi Arabia with a “defense umbrella.”

Unfortunately, this approach hasn’t succeeded at relieving tensions. Most recently, Saudi King Salman pointedly declined to attend a Camp David security summit meant to reassure anxious Persian Gulf nations.

Some analysts argue that U.S. diplomacy with Iran will inexorably fray U.S. alliances in the Middle East, and that the U.S. should placate its allies by revising the current nuclear deal or abandoning negotiations altogether in favor of a military strike.

But historical precedent suggests that the U.S. can manage unhappy reactions by its allies without abandoning sensible diplomacy with its adversaries. By exploiting Saudi Arabia’s military dependence, U.S. policymakers can keep its ally from pursuing nuclear weapons while concurrently advancing Washington’s broader regional agenda.

As I show in a recent article, the United States faced a similar dilemma of alliance management with one of its closest Cold War allies: West Germany. Much like the Saudis today, West German leaders were anxious throughout the 1950s and 1960s about the credibility of U.S. security patronage, and feared that domestic pressure to spend less on American troop deployments overseas would lead the U.S. to withdraw from Europe.

West Germans were also angry over U.S. efforts in the 1960s to reach arms control agreements with the Soviet Union, including the Limited Test Ban Treaty and the Nuclear Non-Proliferation Treaty (NPT). And like the Saudis, German leaders sought to reduce their dependence on the U.S. by reaching out to other allies and by pursuing nuclear weapons.

Toward this end, the West German government began negotiations with France and Italy in the late 1950s on joint production of nuclear weapons, as well as secret discussions in the early 1960s about financing French uranium enrichment efforts in the hope that France would eventually provide Germany with nuclear weapons of its own.

Rather than abandoning negotiations with the Soviets to placate West Germany, U.S. policymakers adopted a strategy of coercive pressure. Specifically, President Kennedy threatened that if West Germany tried to acquire nuclear weapons, the U.S. would rapidly withdraw its military forces from German territory.

This led Germany to affirm its non-nuclear status in 1963 by disavowing nuclear cooperation with France and signing the Limited Test Ban Treaty. Later, when West German leaders balked at permanently renouncing their country’s nuclear option, the Johnson administration once more employed coercive pressure.

As National Security Adviser Walt Rostow reminded a visiting German parliamentary leader in 1968, any German decision to acquire nuclear weapons would “tear apart the alliance” and expose Germany to “a very difficult period during which you might well be destroyed.”

At the same time, managing West Germany’s anxiety required U.S. promises that nuclear restraint would be rewarded with continued military protection, a commitment embodied in the ongoing presence of U.S. troops on German territory and in German integration into NATO’s Nuclear Planning Group.

Thus, to constrain West Germany’s nuclear ambitions while achieving broader U.S. foreign policy objectives, Washington employed both reassurance and coercion.

The U.S. experience with West Germany during the Cold War offers important lessons for its current approach toward Saudi Arabia. Just like West Germany, Saudi Arabia depends on the United States and its partners for arms, training, and support.

As a result, Washington could credibly threaten a military embargo to deter Riyadh from acquiring nuclear weapons, exploiting Saudi officials’ existing anxieties about how committed the U.S. is to their country’s security. Moreover, an embargo threat would be backed by U.S. law, which forbids U.S. military or economic aid to any country that acquires nuclear explosive devices.

In principle, Riyadh could try to discourage a military embargo by threatening to cut off or cut down the supply of oil to the United States. But rapid growth in North American hydrocarbon production has reduced U.S. dependence on oil imports, undermining Saudi Arabia’s economic leverage.

To be sure, the two situations are not precisely the same. Unlike West Germany, Saudi Arabia does not rely on U.S. troops or nuclear weapons to protect its territorial integrity, and it can seek advanced armaments from suppliers other than the United States.

Finding adequate substitutes for U.S. conventional arms will be difficult, however, because Saudi Arabia’s existing stocks of U.S. military hardware are not necessarily interoperable with hardware from other countries, and because these systems rely on U.S. spare parts and technical assistance to remain functional. If the U.S. decides to end its military assistance and cooperation, it could cripple Saudi Arabia’s military forces.

This coercive strategy will not succeed without corresponding assurances. Specifically, the U.S. must promise its Saudi partners that in exchange for their acceptance of U.S. diplomacy toward Iran, Riyadh will receive national security benefits, including the provision of sophisticated armaments and training, cooperation against Iran’s regional provocations, and support for military operations that satisfy both countries’ interests.

These assurances do not necessarily require the full commitment of a treaty, since the U.S. previously showed it would employ force to protect Saudi security during the Gulf War, and recently provided intelligence and logistical support for Saudi-led military operations in Yemen. U.S. military dominance means that no substitute exists for these services. As a result, the Saudis must depend on the U.S. military, making it harder for them to hold out for stronger commitments.

In sum, if U.S. policymakers believe that a framework agreement constraining Iran’s nuclear capabilities advances U.S. security interests in the region, they will be able to contain Saudi opposition by employing both reassurance and coercion. Doing so will enable the United States to deepen its relations with allies, engage in pragmatic diplomacy with adversaries, and contain the spread of nuclear weapons.

This article was written by Gene Gerzhoy  for The Washington Post on May 22, 2015. Gene Gerzhoy is a Post-Doctoral Research Fellow with the Project on Managing the Atom and the International Security Program at the Harvard Kennedy School’s Belfer Center for Science and International Affairs.