Titanium spy planes during the cold war were built by The Americans... from Titanium that they covertly purchased from an unsuspecting Soviet Union.
The Cold War was essentially a war between the United States and the Soviet Union, only fought through allies instead of directly. Tensions were high throughout the entire thing, with the threat of nuclear war looming.
One of the most important technologies of the war was the spy plane. These plane were used by both sides to avoid being detected by radar to better carry-out missions and avoid unwanted attention.
The Americans were trying their hardest to build the best spy plane they could. They tested out planes at the famous Area 51, and often had to hide the planes on a moment’s notice when a soviet satellite would pass overhead.
They were working on a plane called the A-12. It was the first plane to use primarily titanium, which was necessary to withstand the high temperatures the plane would be exposed to while remaining relatively light.
The supplier of titanium the government used for this was running low on the material, so it had to be bought from other places around the world. One of those places was the rival Soviets!
In his book about the time he worked on the plane, Ben Rish said "Our supplier, Titanium Metals Corporation, had only limited reserves of the precious alloy, so the CIA conducted a worldwide search and using third parties and dummy companies, managed to unobtrusively purchase the base metal from one of the world's leading exporters - the Soviet Union."