"There is at least one occasion in which Lightnings served with Axis forces, joining the list of aircraft which served on both sides during World War II. The Regia Aeronautica managed to obtain an intact P-38G when it had been forced to land on Sardinia on July 12, 1943 due to navigation equipment problems during a flight from Gibraltar to Malta. The captured P-38G was repainted in Italian markings and was flown to the experimental center at Guidonia for evaluation. It was flown from there on August 11, 1943 by Col Angelo Tondi to intercept American bombers. Tondi is credited with possibly shooting down one B-24D Liberator. However, the Italian P-38G was grounded shortly thereafter because of a lack of spare parts.
The Italians acquired additional Lightnings in a more orthodox manner six years later. When Italy joined NATO, the Aeronautica Militare Italiana received 50 Lightnings (P-38Js, P-38Ls, and F-5Es), which operated them until they were replaced by jets. "