Iran’s objectives in Syria appear to be focused on creating a land bridge that will provide a route from Tehran to the Mediterranean, and align Syria and Lebanon to them, thereby ensuring launching points for a war against Israel.

As the United States completed its withdrawal from Iraq in 2011, Syrian President Bashar al-Assad’s regime was under increasing pressure from the facing an uprising after its suppression of protests that spring. The Iraqi government then allowed Iranian aircraft to use their airspace to get to Syria.

Via this air corridor, Tehran built Hezbollah’s arsenal to be more heavily armed than it was on the eve of its 2006 war against Israel. Iran has also assisted Hezbollah with the technology to establish missile factories. The air corridor has also given Iran the mean to transport Shiite militia fighters and their families to Syria.

According to Emanuele Ottolenghi, senior fellow at the Foundation for Defense of Democracies, over the years, Iran has supporting the Assad regime’s ethnic cleansing of the Sunni countryside, and, “Most importantly, through its steadfast and successful support of the Assad regime, Tehran has secured its hegemony over Damascus, making it possible for its Islamic Revolutionary Guard Corps, or IRGC, to permanently deploy within shooting range of Israel’s border with Syria.”

The air corridor to Syria and Lebanon is preferred over maritime routes, as ships leaving from Iranian ports take a long time to reach Syria due to an ongoing U.N. arms embargo against Iran. These ships are at constant risk of interdiction in the Mediterranean and the Red Sea. In fact, in 2002, Israel seized an Iranian shipment of 50 tons of arms to the Palestinian Liberation Organization during the Second Intifada, and in 2009, U.S. forces seized arctic cargo ship MV Monceghorsk in the Red Sea, which was carrying 2,000 tons of weapons to Syria. As well, during that same year, Israel intercepted 500 tons of weapons destined for Hezbollah, on the ship MV Francop.

Prior to Baghad opening its airspace in 2011, Iran sent cargos by plane to regional airports, then transported the cargo by truck across the Iraq-Syria border. Sometimes shipments traveled by sea to Sudanese ports and then by truck to where they could cross into the Sinai Peninsula on small ships. Israel, however, disrupted those routes with bombing convoys. Iran was happy to take advantage of the newly opened airspace, and launched an airlift that continues to this day.

The U.S. Department of Treasury sanctioned Iran Air and Mahan Air, two of Iran’s largest airlines, for their shipments of weapons to Iran’s proxies abroad. The planes continued to fly, despite the sanctions.

The airlift escalated in 2015, when rebel forces stood up to Assad’s army and Iran’s. IRGC Quds Force Commander Qassem Suleimani, flew to Moscow to coordinate a strategy that would reverse the course of Syria’s civil war. A massive increase of weapons and military personnel were necessary, that would be transported via hundreds of flights a year by Iranian and Syrian aircraft, many of which were commercial airliners. Iran Air participated in the airlift, and Mahan continues to fly. Almost 1,500 flights have been logged, since the airlift began.

Last year, the Washington Institute for Near East Policy’s Farzin Nadimi assessed that during a two-month period, the airlift brought 21,000 passengers and 5,000 tons of supplies to Damascus.

President Donald Trump has not yet taken action to disrupt Tehran’s airlift, but new sanctions may be the best alternative.

With the implementation of the JCPOA, known as the nuclear deal, three decades of U.S. sanctions against Iran’ came to an end. Tehran began signing deals with Boeing and Airbus. Nine new aircraft have already been delivered to Iran Air, with hundreds more expected. It is reported that Iranian carriers have negotiated and signed deals for more than 300 aircraft, plus spare parts, technical assistance, and maintenance, with the world’s two largest aircraft manufacturers — Airbus and Boeing — as well as smaller producers such as Canada’s Bombardier and Brazil’s Embraer.

These deals cannot proceed without export licenses from the US Treasury Department, and there is good reason to believe that cancelling the deals would disrupt the air corridor.

The nuclear deal is currently on shaky ground, and with the international business community waiting to hear the US president’s May 12th decision on whether to stay or abandon it, credit lines to Tehran have been slow to materialize. The deals with Airbus and Boeing will signal the global financial market that Iran is open for business. If the Trump administration cancels those deals, Iranian prospects of real economic dividends will evaporate.