Al-Tanf (U.S. military base)

In May 2015, Islamic State of Iraq and the Levant (ISIL) militants captured the border checkpoint at Al-Tanf, thus obtaining control over the full length of the Iraq–Syria border. The U.S.-backed New Syrian Army rebel faction captured the al-Tanf post on the Syrian side of the border in early March 2016, and in early August, the al-Waleed checkpoint on the Iraqi side of the border was recaptured by pro-government Iraqi tribal militias backed by U.S.-led forces.[7][8] In August 2016, the BBC published photographs taken in June that year which it said showed British special forces soldiers apparently guarding the perimeter of the al-Tanf base.[9] In March 2017, the Revolutionary Commando Army (the successor of the New Syrian Army) re-opened the border crossing, resuming cross-border civilian traffic; a group referred to as the Army of Iraqi Tribes was said to control the Iraqi side of the crossing.[10]

On 8 April 2017, ISIL fighters launched a complex and coordinated attack against the U.S. special forces outpost at al-Tanf.[11][12] ISIL started the attack by striking the base with a car bomb and then attacking with 20-30 infantry. The attack was repelled first by gunfire from the rebels and U.S. special forces, then by multiple airstrikes from the anti-ISIL coalition which killed most of the ISIL force and destroyed their vehicles. Rebels stated that four of their fighters and eight ISIL fighters were killed.[13]

On 18 May 2017, U.S. fighter jets struck a convoy of pro-Syrian government forces advancing towards the base.[14][15] Shortly thereafter, Syrian government forces were reported to continue their advance in a direction that suggested their intent might be to outflank and isolate al-Tanf;[16] the government forces appeared to use advanced Russian-made weapons and were supported by Russian helicopters, according to a report acknowledged on May 26 by the Russian Defence Ministry′s media outlet.[17]

On 17 June 2017, the Iraqi Armed Forces announced that the Iraqi Army and Sunni tribal fighters, supported by U.S.-led Coalition aircraft, had dislodged ISIL from the Iraqi side of al-Waleed border crossing.[18]

3rd Battalion, 7th Marines attached to Special Purpose Marine Air-Ground Task Force – Crisis Response – Central Command during a live fire exercise near Al-Tanf, 7 September 2018

At the end of December 2017, the chief of the Russian General Staff Valery Gerasimov said that the U.S. garrison at al-Tanf was fully isolated by Syrian government forces following the desert offensive in the area.[19][20]

"The 55 KM area"

U.S. Green Berets conduct a medevac exercise during a patrol within the Deconfliction Zone, 27 May 2020

By late 2017, Arab media began calling the "deconfliction area" around the Tanf base "The 55 KM area" as it composed of a half-circle area with a radius of 55 km with the base at its center. By 2018, the al-Tanf area hosted five rebel factions including the Lions of the East Army, the Forces of Martyr Ahmad al-Abdo, the Army of Free Tribes, the Revolutionary Commando Army (also known as Maghawir al-Thawra (MaT)), and Al-Qaryatayn Martyrs Brigade.[21]

On 7 September 2018, United States Central Command announced an Operation Inherent Resolve live fire exercise around the al-Tanf garrison. The announcement described it as a "defeat-ISIS exercise".[22] The Russian Reconciliation Center for Syria commented that "during the existence of the base, we don't know of a single US operation against IS [Islamic State, formerly ISIS] in the area."[23][3]

By 2019, the CJTF-OIR coalition referred to the area simply as the Deconfliction Zone (DCZ) with the Al-Tanf Garrison (ATG) at the center. On 23 October 2019, Maghawir al-Thawra reportedly seized $3.5 million worth of illicit drugs from a smuggler within the DCZ. According to CJTF-OIR, the smuggler hid the drugs under the normal guise of supplies being transported to the Rukban refugee camp. MaT searched the smuggler's truck and found nearly 850,000 Captagon pills. "This is one of the biggest drug busts we have ever had," said Col. Muhanned Tallah, the MaT commander. The coalition linked weapons and drug smuggling within the DCZ to ISIL underground networks.[24]

Around February 16, 2020, an Iranian-backed proxy group reportedly breached the deconfliction zone at Al-Tanf, and were then repelled by the U.S.-partnered Maghawir al-Thawra.[25][26]

On April 16, 2020, a number of Syrian rebels at al-Tanf base defected to the Syrian government in a convoy.[27]

The U.S. refers to the Revolutionary Commando Army as part of the "Vetted Syrian Opposition". According to the U.S., these fighters are permitted only to launch offensives against ISIL and not against the Syrian Armed Forces, though clashes with pro-Syrian government elements have occurred.[11][12]

In September 2017, Russian government-owned media outlet RIA Novosti reported, with a reference to unnamed military and diplomatic sources, that the U.S. had voiced readiness to leave al-Tanf but did not say when.[28]

On 8 February 2018, following "an unprovoked attack" by the pro-Syrian government forces in eastern Syria, the Syrian Democratic Forces and U.S.-led Coalition inflicted multiple casualties among Russian private military contractors of the Wagner Group, the Russian foreign ministry spokesperson, Maria Zakharova said: "The unlawful US armed presence in Syria presents a serious challenge to the peace process and to the country's territorial integrity and unity. A 55-kilometer zone unilaterally created by Americans around their military base near al-Tanf is being used by the scattered units of ISIS militants" for evading pursuit by government forces and re-grouping.[29] In mid-February 2018, Russia's foreign minister Sergey Lavrov, in an exclusive interview with Euronews, said that U.S. military presence in Syria generally and in the area of al-Tanf specifically "was illegal and unacceptable."[30][31][32]

In August 2018, U.S. State Department representative William V. Roebuck traveled to the cities of Manbij and Kobanî, both situated in Aleppo Governorate, as well as the town of al-Shaddadah in Hasakah Governorate. He was later due to visit Deir ez-Zor Governorate, half of which is held by the Kurdish-led Democratic Federation of Northern Syria. "We are prepared to stay here, as the president Donald Trump has made clear," he said after meeting with Kurdish officials.[33][34]

After the announced withdrawal of U.S. troops from Syria, U.S. National Security Advisor John Bolton said in early 2019 that U.S. operations in the al-Tanf area would continue as a part of the U.S. effort to counter "Iranian influence" in Syria.[6] On 28 January 2019, Jordanian Foreign Minister Ayman Safadi ruled out the prospect of Jordanian forces seizing control of al-Tanf after American ground troops leave Syria. "Al-Tanf is on the other side of the Jordanian border. As I said, Jordan will not cross its border. We will take every measure we have to protect our security...but arrangements on the other side of the border after withdrawal will have to be agreed by all parties, and they have to ensure the safety and security in the area," Safadi said.[35]

The Trump administration announced on 22 February 2019 that around 400 U.S. troops would remain in Syria post-withdrawal, with about half garrisoned in the Democratic Federation of Northern Syria and half at the al-Tanf garrison.[36] The 200 at al-Tanf were to remain indefinitely.[37]

U.S. Green Berets and Maghawir al-Thawra (MaT) on a joint patrol near Al-Tanf, 29 April 2020

On 27 February, Syria and Russia released a joint statement again demanding all U.S. forces leave Syria, while also demanding U.S. forces allow Russian and Syrian authorities to evacuate the Rukban refugee camp along the Jordanian border to "relocate people in the Rubkan area and guarantee them safe passage to their places of permanent residence". Russia argued that the U.S. was holding the refugee camp "hostage" and potentially as human shields within the territory.[38][39] According to a 24 March report by the U.S. government-funded Voice of America, the U.S.-backed Revolutionary Commando Army rebel group, which maintains aid access and provides security for the Rukban camp, said both refugees and U.S.-backed rebels in the zone depended on U.S. protection against attacks by pro-Syrian government militias and Islamic State-affiliated jihadists. A Rukban camp spokesman asserted that it was the Syrians and Russians that were "embargoing" the camp to force the refugees into reconciliation and to pressure U.S. troops to leave the strategically important al-Tanf military base.[40]

On 4 June 2019, representatives of more than 30 countries participated in a meeting with the command of Operation Inherent Resolve in Kuwait where the issue of stepping up efforts to fight terrorism in Iraq and Syria was discussed.[41] Amid a period of heightened regional tensions with Iran, the Pentagon announced on 18 June that another 1,000 troops will be deployed to the Middle East, presumably including the U.S. base in Syrian al-Tanf.[42]

In October 2019, in the context of the pullout of American troops from northern Syria, The New York Times reported that the Pentagon was planning to "leave 150 Special Operations forces at a base called al-Tanf".[43]

• List of United States military bases in Syria
• American-led intervention in the Syrian Civil War
• Timber Sycamore
• Foreign interventions by the United States

• First Came ISIS, Then Iran: How the Mission at a U.S. Base in Syria Kept Growing, The New York Times video