Iran and the P5+1 finally have a deal. This first-step accord requires Iran to put in place significant curbs on its nuclear program in exchange for temporary and limited sanctions relief. It marks a historic moment in Iran’s foreign policy, and could be the harbinger of an eventual détente between Tehran and Washington. The agreement has been widely hailed as a success within the international community and in Iran, where even the Supreme Leader congratulated his diplomatic team for their achievement.

But this is just the beginning of what will likely be a difficult and contentious process. Beyond agreeing on details that would permanently neuter Iran’s nuclear program, a final deal would also be contingent on the enduring buy-in of potential spoilers in Iran and elsewhere. Members of Congress for instance, who have already drafted additional sanctions, will be eager to respond to any hesitation or backtracking by Iran. Similarly, hardliners in Iran, while tacitly supportive of the deal so far, might move against it if they feel their interests are at-risk. Regional politics, particularly Syria’s civil war and the seething cold war between Iran and Saudi Arabia, could also threaten the deal or impact future deliberations. Failure is therefore a distinct possibility and all sides should be aware of it.

The agreement curtails and rolls back significant portions of Iran’s nuclear program for the next six months. Among Iran’s concessions is a cap on uranium enrichment levels at 5-percent (down from the current level of 20-percent). Iran will dilute half of its stock of 20-percent enriched uranium down to 5-percent and will not be allowed to reconvert it (the other half will be reserved for use in the Tehran Research Reactor). Advances at the Natanz, Fordow and Arak facilities will be halted, and Iran will be barred from building any new enrichment locations. Iran will also have to abide by a number of other protocols aimed at reducing or diluting its stockpile.

To ensure Iran sticks to its side of the bargain, the IAEA will be given extensive and intrusive access to Iran’s nuclear sites. The IAEA will increase the frequency of its inspections of Iran’s enrichment facilities at Natanz and Fordow from weekly to daily. In addition to other obligations, Iran will be required to provide the IAEA with requested information and plans for the Arak heavy water plant, and declare all new nuclear facilities.

In exchange, Iran gets some desperately needed, albeit temporary and reversible, sanctions relief. No new sanctions on Iran’s petroleum sales will be put in place, and the sanctions targeting insurance and transportation of oil will be suspended. U.S. and EU sanctions on Iran’s petrochemical exports, gold and precious metals, and auto industry will also be suspended. Financial channels will be established to enable Iran to import food, medicine, and other “humanitarian trade” currently affected by sanctions. All told, the relief package could be worth around $7 billion for Tehran.

Iran also gains some breathing space. The combination of sanctions and simmering regional tensions has left Iran embattled. Iran is knee-deep in Syria’s civil war, where its support to Assad has thrust it into a conflict with Saudi Arabia and countless Sunni rebel groups. The war has tied up Iran’s main allies in Assad and Hezbollah for the foreseeable future, and caused sectarian discord in the region to spike. Spillover has led to increased sectarian violence in Iraq and Lebanon, and spawned a wave of antipathy against Iran in the region—evinced, most recently, in a bomb attack on Iran’s embassy in Beirut.

Iran has relied on its ties to Hezbollah, Syria, and groups such as Hamas (whose fighters now battle against it in Syria) to keep pressure on Israel and by extension to deter the United States. But with these equities under threat, Iran’s leverage against Washington is also slipping. Iran has two choices: it can maintain the status quo and bet that the Syrian war can be managed without much more blowback; or it can look for ways to alleviate the pressures suffocating its economy and weakening its regional position. Iran is unlikely to abandon its strategic interests in the Levant, which leaves a nuclear deal the best (or, as Iran’s hardliners might see it, as the least bad) option for Tehran to regain some of its strength and dignity. If the interim accord reached in Geneva (not to mention the backchannel talks between Tehran and Washington that preceded the deal) is any indication, Iran is probably serious about finding a workable compromise with the West.

So if a nuclear deal strengthens Iran, how could it also benefit the United States? First and foremost, finding a diplomatic solution to Iran’s nuclear program will help America avoid going to war with Iran. Although pundits have advocated military strikes against Iran’s nuclear facilities in the past, the Obama administration and defense officials likely understand just how costly, unpredictable and ineffective an elective war with Iran would be. The current deal puts significant restraints on Iran’s nuclear program and establishes additional safeguards to ensure Iran sticks to the pact. Iran’s program will be more transparent and more closely monitored as a result. Also, should a long-term deal not be reached, the current agreement will at least have effectively pushed back the timeline of any possible Iranian breakout capability. This is all achieved at relatively little cost to the United States. Each aspect of the sanctions relief package can be reversed and additional sanctions placed on Iran should it default on any part of the deal. The onus is on Iran to follow through on its obligations. If it fails to do so, the Obama administration can credibly say it gave diplomacy a try and return to a more forward-leaning strategy toward Iran.

There is much to celebrate with this deal. It marks the starting point of what will hopefully be a peaceful and sustainable solution to Iran’s nuclear quest and an end to nuclear proliferation in the Middle East. The United States got Iran to meet its demands, yet Iran was also able to save face. Everyone is happy, for now. As difficult as negotiations were, putting the deal into action and agreeing on a final, end-state compromise will take much more work. A final deal will also not solve tensions between the United States and Iran. The United States will and should continue to regard Iran’s involvement in Syria, support for Hezbollah, simmering conflict with Israel, and human-rights abuses at home as unacceptable. A nuclear deal will thus be only the beginning of a very long road toward a possible détente between Washington and Tehran. However, if a final deal cannot be reached, we will be back to square one—except in that eventuality there would no longer be a diplomatic solution.

Afshon Ostovar is a senior analyst at Center for Naval Analyses and the author of a forthcoming book on power and politics in post-revolutionary Iran.