During the years of the Great Patriotic War, almost a quarter of all military cargo received by the Soviet Union under the lend-lease passed through the "Iranian corridor" - through the Persian Gulf from the Iraqi port of Basra by rail to the Soviet-Iranian border. However, on June 30, 1941, in a conversation with Soviet Ambassador Smirnov, Iranian Prime Minister Mansour said that Iran would not give consent to the transportation of weapons through its territory. On July 5, the Iranian Shah Reza Pahlavi confirmed the refusal to transport military cargo to the USSR.
On June 25, Hitler demanded that Iran enter the war on Germany's side. “Since June 22, the Iranians have been deploying military units, weapons and ammunition to the border with the USSR. The construction of military facilities was accelerated, heavy guns were installed on the Caspian coast in the Rasht-Pahlavi region by order of the shah, ”a Soviet intelligence resident reported on June 29 from the Iranian port of Pahlavi. At a meeting of the Supreme Military Council of Iran held at the end of June, 24 out of 40 voters voted for neutrality, and 16 generals agreed with the German demand. On the streets of Tehran, leaflets suddenly appeared with claims to the USSR to return 19 cities that had passed to Russia during the Azov campaigns of Peter I. On June 26, the Soviet side warned the Shah that German agents were preparing a coup d'etat in Iran, but this message, as well as subsequent was ignored. On July 14, the British ambassador to Moscow, Crips, proposed to back up diplomatic pressure on the Shah with military action. On August 15, Reza Pahlavi gave the order to start a general mobilization. On August 25, 1941, the USSR and Great Britain simultaneously sent their troops into Iran.
The Iranian army was unable to provide organized resistance. For example, the garrison of the port of Pahlavi of 520 people was captured by a reconnaissance detachment of 45 soldiers of the Red Army. The 10th Iranian division, which occupied advantageous high-altitude lines in the Mashhad area, completely dispersed. The commander of the defense of Ardabil, General Qaderi, abandoned the troops and left, at the same time taking over cars for the removal of his personal belongings. On August 30, Iranian troops ceased resistance.
On September 7, a meeting of Soviet and British soldiers took place in the town of Qazvini. “The joint actions of the British and Soviet troops predetermined the matter. This will continue to be so, since our troops will act together, ”Stalin expressed his satisfaction with the results of the operation in his message to Churchill.
On September 8, an agreement was signed, according to which Tehran expelled all citizens of Germany and its allies from the country, and pledged not to hinder and assist the transit of military cargo from England to Russia. On September 17, Shah Reza Pahlavi, under pressure from the British, was forced to abdicate in favor of his son.
On the same day, Tehran welcomed the arrival of the Red Army:
“The streets were full of people. Thousands of people greeted Soviet soldiers and commanders with applause and enthusiastic greetings.
- Zindebad Erteshi Sorh! Long live the Red Army! Hooray! - joyous shouts were heard from all sides. Someone, rushing forward, showered the passing soldiers with flowers. "
Soviet troops remained in Iran until the summer of 1946.