In a landmark deal, Boeing finalized its contract with Iran Air for the sale of 80 civil passenger aircraft, including 50 737s and 30 777s. The aircraft will cost Iran Air $16.6 billion and will be delivered over a period of 10 years, beginning in 2018. How the sale will be financed remains unclear, but the parties have evidently discovered a mechanism for ensuring that payment will proceed apace. News of the Boeing deal follows last month’s reports that Airbus had been fully licensed by the U.S. Department of the Treasury’s Office of Foreign Assets Control (OFAC) for the sale of its aircraft to Iran. Clearly, Boeing has received the full bevy of license authorizations required to undertake this sale – a fact confirmed by Boeing’s representative at the contract signing in Tehran yesterday.

Undeniably, the signing is an important, if not historical, step. No insignificant hurdles – including the need to agree to contract terms, the licensing requirement from U.S. authorities, the difficulties in finding the financing to support this deal – presented themselves over the past twelve months. Turning a mere Memorandum of Understanding (MOU) into an enforceable contract represents a victory for all involved, including the Obama administration (which was presented with unforeseen difficulties in licensing the export of aircraft to Iran).

Nonetheless, this is far from the end of the road. Indeed, the fight is only truly beginning, as the incoming Trump administration threatens to invite persons notoriously hostile to the budding rapprochement between the U.S. and Iran into the new administration and members of Congress continue to push for a legislative revocation of the license authorizations. As I have noted previously, the licenses granted to Boeing and Airbus alike will certainly contain provisions expressing OFAC’s authority to revoke the licenses without prior notice. As a result, while Boeing is today authorized to export aircraft to Iran, there is no guarantee that it will be likewise authorized to do so tomorrow. Boeing’s ability to fulfill its contract terms with Iran Air will be wholly dependent on OFAC’s continued assent to the aircraft sale.

Understanding this, Boeing has not shied from defending itself in the realm of public opinion. At the same time that news reports came out that Boeing had finalized its sale with Iran Air, Boeing released a press statement noting that the sale would help “support tens of thousands of U.S. jobs directly associated with production and delivery of the 777-300ERs and nearly 100,000 U.S. jobs in the U.S. aerospace value stream for the full course of deliveries.” Not surprisingly, Boeing is tailoring its public messaging regarding the sale to Iran to President-elect Trump’s focus on jobs. On this, Boeing has a point.

Less expressed, however, is what this Boeing deal signifies for the future of the U.S. trade embargo with Iran. For more than two decades, the United States has imposed a comprehensive trade and investment embargo with Iran – the prohibitions of which are codified at 31 C.F.R. Part 560, the Iranian Transactions and Sanctions Regulations (ITSR) – prohibiting virtually all transactions between the two countries with limited exceptions. By specifically licensing Boeing to sell U.S.-made aircraft to Iran, the Obama administration has carved a narrow but significant exception to the trade embargo, as one of the largest U.S. companies prepares to engage in a multi-year, multi-billion dollar deal with the flag carrier airline of the Islamic Republic. While some will contest that the deal has no consequences to the wider embargo, a narrow carve-out undertaken for humanitarian purposes, there should be no mistake that a sale of this size with Iran breaks more than a few taboos and opens the door to a broader licensing regime with Iran, if not a lifting of the embargo writ large. The variable that is the President-elect puts a lot of this up in the air, but as I believe and as agreed to by former U.S. officials I have spoken to, President-elect Trump is just as likely to lift the embargo as he is to revoke the licenses given to Boeing to undertake this sale. In short, Boeing’s contract with Iran Air could represent a major turning point in the U.S.’s trade relationship with Iran, undoing a decades-old embargo and upending the practice of U.S. economic sanctions related to Iran.  Time will tell, but Boeing’s deal with Iran Air represents a significant development that should not go under-appreciated.