THE Tu-4: IMITATION IS THE SINCEREST FORM OF FLATTERY

As an ally of the Soviet Union in its fight against Germany during the Second World War, the United States provided Brobdingnagian quantities of armaments and other materials to assist the Reds in that conflict. One item requested more than once by the Russians, and refused every time by the Americans, was the Boeing B-29 Superfortress heavy bomber. 

The B-29 was developed to carry 20,000 pounds of explosives up to 4,100 miles away in order to rain fire (and ultimately two atomic bombs) on the Empire of Japan. You may wonder, provided that you have read this far, why didn't the USA, instead of designing a new bomber, simply station some of its bombers already in its fleet, like the B-17 or B-24, in Siberia in the Soviet Union and use those to fly the relatively shorter distances to Japan? Well, there may have been logistical problems in establishing American air bases in the remote areas of eastern Siberia (as if there were non-remote areas of eastern Siberia), but the more pressing consideration was that while the Americans were allies of the Soviet Union in fighting Germans, the Soviets were not allies of America in its conflict with Japan. With respect to the Japanese-American war, the Russians were neutral, just like Switzerland--at least until August 8, 1945, when the Soviets finally declared war on Japan two days after the Hiroshima bombing.  

Although I do not know of the specific reasons cited by the Americans for their refusal to supply the Soviets with B-29s, one could easily speculate that the USA wanted them all itself in its campaign against Japan and further saw little good arising from giving a potential foe in the future a long-range heavy bomber, especially when the Russians really did not require one in its fight against Germany. However, Stalin wanted B-29s, so what to do, what to do? 

Well, during the course of the war, four American B-29s on bombing raids to Japan landed or crashed on Soviet soil. Pursuant to international law, the Soviet Union, as a neutral country, interred the crews and kept the planes. Some of the crews were sent to camps near the border of Iran. Depending on your viewpoint, Iran was either a member of or occupied by the Allied Powers, and the flight crews were able to easily "escape" into Iran with the tacit approval of the Russians and into friendly hands. Their planes still remained behind until after V-J day, when the Soviets returned one and a remaining crew back to the United States. 

No one outside of the Soviets knew what happened to the remaining aircraft until the Aviation Day parade in Moscow on August 3, 1947. At that event, three B-29s majestically flew overhead. Western observers concluded that these must have been the three planes which had remained in Russia. Then, a fourth Superfortress appeared. It was apparent, much to the dismay of the Americans, that the Soviets had reverse-engineered the B-29 and now had an aircraft capable of bombing Los Angeles or Chicago on a one-way mission (or, once in-air refueling was perfected, on a round-trip run). The fact that the Russians exploded their first atomic bomb later that same month did little to assuage the concerns of the Americans. 

Stalin had issued strict orders to mobilize over 900 factories and design centers to produce exact clones of the B-29s based on the examples in Soviet custody. Stalin made it clear that "exact" meant "exact." Stalin's myrmidons strictly complied with Stalin's decree (which was a smart thing to have done if you were a myrmidon of Stalin).  In fact, one of the downed American planes had been hit with Japanese fire on an earlier mission and sported a repair patch covering the damage. The Soviet drones methodically put a patch on the same place on the cloned planes. Even if the Soviets had a better design already available for a particular component, they dutifully copied the American version instead. There were in fact a few deviations made (such as the use of Russian parachutes), but only after review by the highest authorities. 

The Soviets built about 847 of these aircraft, which they designated as the Tu-4, until the end of production in 1952. They were the first Soviet strategic bomber, and, like their American counterpart, the first plane to drop an atomic bomb for its nation.