I suppose it was a case of "needs must". "Just how did the post-war Israeli air force end up equipping its first fighter squadrons with the famous Nazi warplane the Me-109s? After approval of the Partition Plan of Palestine in November 1947, the UK, who had been the governing power continued to supply weapons and ammunition to Egypt and Trans-Jordan. However, the entire world imposed an immediate embargo on sale and shipment of military equipment to Israel. The only exception was post war Czechoslovakia, which agreed to sell a substantial amount of German-designed rifles, machine guns, ammunition, and even fighter planes to the Jewish state. The problem for the infant state of Israel, was transporting the vast quantities of weapons over 1800 miles. The main obstacle they faced, was Czechoslovakia being a land-locked nation, surrounded by countries that would not allow transhipment of arms in violation of the embargo. The buying agents for Israel overcame this by chartering a C-54 transport plane and seven C-46s, originally purchased as war surplus in California. The pilots and crews from the newly formed Israeli Air Force Air Transport Command then began an airlift that would astound the world. As part of the deal, the Israeli agents negotiated the purchase of Avia S-199s which was a copy of the famous ME109, the backbone of the Nazi Luftwaffe. The Avia S1-99s was constructed with parts and plans left over from Luftwaffe aircraft production that had taken place under the country’s German occupation of Czechoslovakia during the war. One of the main aircraft they produced was a copy of the Messerschmitt Bf 109G-6s under the Avia S-99 name, however, they soon ran into problems when they ran out of the ME-109′s Daimler-Benz DB 605 engine. This resulted in an inferior alternative engine been used. It was decided that as a replacement for the original engine, the aircraft would use the same engine (Junkers Jumo 211 F) and propeller of the Heinkel He 111 bomber." http://www.heritagedaily.com/2013/09/when-israel-flew-nazi-planes/99090?