For two years the United States has delayed action on a Qatari attempt to buy 36 (and eventually 73) F-15E fighter bombers (for nearly $4 billion) and Kuwaiti efforts to buy 28 F-18E fighters (for $3 billion). The American Department of Defense and State Department approved the deal and there was support in Congress but for reasons unclear the American president refused to approve (or disapprove) the deal or even explain why not.
Kuwait has long used the older F-18A and wants the latest model to improve its defenses against an increasingly aggressive Iran next door. With a max weight of 29 tons, an F-18E can carry up to eight tons of bombs. Combat range is 720 kilometers, and the aircraft was designed as a fighter.
Qatar still wants the F-15E, which Israel and Saudi Arabia are both major users of but in the meantime has bought 24 Rafale fighters from France. It is still a mystery of how tiny Qatar (population 2.2 million) justifies the purchase of over 73 F-15Es.
Middle Eastern nations are major users of the F-15E. Saudi Arabia alone has 153 F-15SA fighter-bombers. This includes 84 new ones ordered in 2012 and 69 upgraded F-15S models. The F-15SA is a special models of the F-15, similar to the two-seater F-15E, and unlike the single seat F-15Cs the Saudis already have optimized for ground attack.
Israel protested selling the Saudis such advanced bomber technology, but the U.S. worked this out via secret discussions. The Saudi "F-15SA" is similar to the South Korean version of the F-15E, the F-15K. This is a customized version of the 36 ton U.S. F-15E (a two seat fighter bomber version of the single seat, 31 ton F-15C fighter). Already in service for over twenty years, the F-15E can carry up to 11 tons of bombs and missiles, along with a targeting pod and an internal 20mm cannon. The Saudi will begin receiving the new F-15SAs in 2016 and those will cost nearly $30 billion.
The F-15E is an all-weather aircraft that can fly one-way up to 3,900 kilometers. It uses in-flight refueling to hit targets anywhere on the planet. For the Saudis this means they can keep these bombers in the air longer, searching for targets. Smart bombs make the F-15E particularly efficient. The second crewman (the backseater) handles the electronics and bombing.
The F-15E remains a potent air-superiority fighter, making it an exceptional combat aircraft. This success prompted Israel, Saudi Arabia, South Korea, and Singapore to buy it, paying about $100 million per aircraft. In the U.S. Air Force the F-15E is one of the most popular aircraft for combat pilots to fly, even more so than the new F-22.