With the Boeing Company coming close to finalising the design of its highly formidable enhanced F-15 Eagle air superiority airframe, the F-15X ”˜4++ generation’ fighter, the new aircraft has gained a great deal of attention not only in the United States - but also among a number of its leading defence clients. The Israeli Air Force, as the oldest foreign operator of the F-15 and one of just three export clients for air superiority variants of the fighter, alongside Japan and Saudi Arabia, has reportedly seen the new design as particularly useful - perhaps ideal - for its lethality and cost effectiveness as a means to modernise its air superiority capabilities. The Israeli military has long had a special relationship with the Eagle, being the first to deploy it in combat with excellent results effect against Soviet built fighters in neighbouring Syria and gaining the vast majority of air to air kills ever achieved with the fighter worldwide. Israel is the only country to field all five major variants of the F-15, the A/B and more modern C/D air superiority fighters acquired from the late 1970s and the more costly F-15E strike fighter acquired from the 1990s. The strike variant of the F-15, making extensive use of indigenous Israeli components, is fielded under the designation F-15I Ra’am, and is distinct from and in many ways superior to the standard F-15E Strike Eagle fielded by United States Air Force. While Israel’s F-15 fleet is highly capable, and the country’s supremacy in the air and its ability to project power across the Middle East rest heavily on the wings of the country’s Eagles, air superiority variants of the fighters date back approximately 40 years - and a number of the country’s potential adversaries have since acquired newer and often more capable systems for their own air fleets. Israel and Japan were expected to be prime clients for the Lockheed Martin F-22 Raptor, the fifth generation analogue to the F-15 much as the F-35 is the analogue to the lighter and less costly F-16, and only a blanket ban by the U.S. Congress on the export of the Raptors prevented the two countries and other potential clients from modernising their air fleets. This had very serious consequences for the balance of power in the air of a number of American allies - and led to Japan losing its air superiority advantage outright relative to its neighbours. Considering the details which later emerged regarding the Raptor’s immense maintenance requirements and operational costs, and Israel’s relatively small economy and limited defence budget, whether the F-22 would in fact have been suitable for the country’s defence needs has been brought to question. Nevertheless with the Raptor unobtainable and the F-15C, the country’s prime air superiority platform, fast ageing, Israel is very much in need of a more capable new air superiority fighter. Enter the F-15X - very likely the perfect fighter for Israel’s requirements.&nbsp;Threats to Israeli air superiority have included neighbouring Egypt’s acquisition of a sizeable MiG-29M fleet, which while lighter than the F-15 and not specialised for air superiority do pose a considerably greater challenge than the light F-16C jets which formerly comprised the mainstay of Egyptian aerial warfare capabilities. The MiG-29M deploy ”˜4+ generation’ technologies superior to the F-15, and while slightly slower and lower flying they are more manoeuvrable, carry superior air to air missiles for a considerably longer engagement range of 130km, and deploy advanced infra red sensors the Eagles lack which allow them to operate without a radar signature. Elsewhere in Africa Sudan has reportedly placed a vast order for Russian next generation air superiority fighters, while Algeria already fields these fighters in large numbers which could deploy from Egypt, Syria or elsewhere in the unlikely but not to be discounted case of a prospective Arab-Israeli War. Syria too appears set to receive vastly modernised new combat aircraft including the ”˜4+ generation’ MiG-29SMT, with similar capabilities to the M variant fielded by Egypt. Damascus has previously shown interest in acquiring MiG-31 heavy interceptors from Russia, and should the country again try to purchase these elite jets it would spell disaster for and effectively bring an end to Israel’s qualitative advantage in the air. Further eastwards the Islamic Republic of Iran, Israel's prime regional adversary, is reportedly planning the acquisition of advanced Su-30 Flanker air superiority fighters from Russia - aircraft considerably superior to the F-15C in their air to air combat capabilities. Tehran's interest in manufacturing the fighters domestically under licence indicates that the Iranian Air Force is considering acquisitions in considerable numbers - allowing it not only to defend its skies but also to project power across the Middle East and even operate offensively against Israeli targets using the Flanker’s long range. Considerable upgrades applied by Iran to its existing F-14 air superiority fleet, supported by several dozen MiG-29 fighters fielding the latest air to air munitions, mean that the Iranian Air Force today, though restricted to defensive operations, already poses a potential threat to Israeli supremacy in the air - with the latest high precision air to air munitions developed for the F-14 giving it an engagement range well over double that of the F-15C. The F-15X will built on the already formidable capabilities of the Eagle airframe, including its high speed, operational altitude and manoeuvrability, while adding advanced next generation features including an active electronically scanned array radar - likely derived from that of the F-22, new AIM-120D air to air missiles with a vastly extended engagement range of 180km, an infra red search and track system, modern avionics and cockpit displays and all new electronic warfare systems. The fighters will reportedly deploy 24 air to air missiles, three times the payload of the F-15C and F-22 and more than any fighter ever developed anywhere in the world. The use of the Eagle airframe ensures not only that Israeli pilots will be highly familiar with the new jet, but also that maintenance costs will not be considerably greater and parts will largely be interoperable with other Eagle variants Israel currently has in service. Israel has already demonstrated a great deal of faith in the Eagle design, deploying the F-15 wherever the fighting is thickest and prioritising the acquisition of further F-15I strike jets over the new fifth generation F-35 - much to the chagrin of Lockheed Martin which insists its new light fighter is superior. Ultimately the F-15X will be a game changer which will remove Israel from its currently dangerous position and ensure its continued qualitative advantage in the skies for years if not decades to come, providing a highly effective complement to the lighter F-35 and the F-15I strike fighters of which further aircraft are currently on order from the United States. While the U.S. Air Force, currently appearing to have focused all its efforts in the air superiority field on the upcoming F-X Air Dominance Fighter, a program to develop a sixth generation air superiority platform to replace the Raptor, may not acquire the F-15X, Israel arguably has a far greater need for the new fighter and is less likely to pass up a seemingly ideal opportunity to upgrade its air superiority capabilities with a next generation variant of a highly familiar airframe.