Operation X

Background

After the July 1936 military rebellion, Germany and Italy supplied the Nationalists with aircraft and technicians, while the Anglo-French non-intervention agreement blocked the supply of major weapons. Under these conditions the Soviet Union was the only state able and willing to arm the Republican government, becoming the Republic's only major source of heavy weapons. The USSR broke the Non-Intervention Agreement and the League of Nations embargo, but unlike Hitler and Mussolini it tried to do so covertly.

Section X and the transport system

Stalin created Section X of the Soviet military to head the weapons shipments, and the operation took its name from that section. Many of the rifles and field guns supplied were old or obsolete, though T-26 and BT-5 tanks and I-16 fighters were modern. Deliveries were slow, and ships carried false decks and deceptive paint and flags to evade the Nationalists.

Scale

Estimates of Soviet material range between 634 and 806 aircraft, 331 and 362 tanks, and 1,034 to 1,895 artillery pieces. Many shipments were lost or arrived incomplete.

Payment and gold

The Republic paid for the arms with the gold reserves of the Bank of Spain, an arrangement Francoist propaganda cited as "Moscow gold". As much as about 72 per cent of Spain's gold reserve, more than US$500 million in 1936 prices, was spent on Soviet arms, while the remaining roughly 27 per cent went to France.

Consequences

Access to Soviet arms was used by the government and the communists to restore control over the war effort. As Republican policy floundered in 1938, Stalin withdrew his troops and tanks, and Hugh Thomas observes that had the socialist and republican members of the government been able to buy arms from the United States, Britain and France, they might have tried to cut themselves loose from Stalin.