Turkey joined NATO in 1952. since 1959 the USA has kept nuclear weapons there in different configurations, for detering to the USSR. Until 1963, the US arsenal consisted of Jupiter missiles and at a later date of B61 type nuclear bombs. In the 1980s there were around 500 US nuclear warheads in Turkey, out of which were 300 bombs can be carried by aircraft. These bombs (up to 200 kilotons) were intended for four Turkish F-4, F-104 and F-100 squadrons deployed in the following airbases: Erhac, Murted (ironically , currently S400 battalion is here), Eskisehir and Balikesir.
The current NATO nuclear arsenal in Turkey consists of upgraded bombs of the same type, having a maximum energy output of 340 kilotons, depending on the specific configuration. None of the aircraft in Turkey, with the exception of the F-16, are able to carry the B61 type nuclear bombs that are used by the Americans. Turkey wants to acquire F-35 fighters which, as estimated, will be adapted to carrying these bombs. (In the last few years, speculation has emerged about the transfer of this arsenal to Romania.)
In 1969 Turkey signed the NPT (the Treaty on the Non-Proliferation of Nuclear Weapons/Technology). In 1982, it reaffirmed the Treaty. Turkey also signed the BTWC (The Biological and Toxin Weapons Convention) and CWC (Chemical Weapons Convention). Moreover, "officially" Turkey opposes the nuclear arming of the Middle East to this day, and attempts to promote the demilitarization of nuclear weapons.
Over the years, Turkey has aspired to develop a civilian nuclear program for the supply of electrical power. Turkey imports most of its energy in the form of fuels and gas, and nuclear energy could provide energy independence. This is the point where concerns regarding a possible military program emerge. A 2014 report on a German website, based on estimates by the German intelligence service, claimed that Turkey was adopting the Iranian model – a civilian nuclear program on the surface, with a military program underneath it, - quite literally.
The Turkish Atomic Energy Commission (TAEC) was established in 1956 for the purpose of engaging in the development of nuclear reactors for the supply of electricity and for research purposes. In 1961, Turkey's first nuclear research center (CNRTC – Cekmece Nuclear Research & Training Center) was established. A year later, a 1-megawatt reactor was built at the center. In 1966, a second research center, ANRTC, (Ankara Nuclear Research & Training Center) was established. Both research centers worked on a program that involved the establishment of a heavy water based nuclear reactor with an output of 300-400 megawatts. But further plans never materialized. Later programs involved the establishment of reactors at Akkuyu Bay and Sinop.
All of these programs were halted following the (US backed) military coup in Turkey in 1980. After the coup, the USA raised suspicions that Turkey was helping Pakistan acquire nuclear know-how. At that time, NATO had stopped the Pakistani uranium enrichment program, and according to some sources the latter turned to Turkey for assistance of nuclear smugling. Suspicions were voiced by the USA to the effect that Turkey was providing Pakistan with nuclear materials that had the potential of being developed for use in nuclear weapons. (no matter how ridiculous) The USA even suspected that Turkey was helping Pakistan enrich uranium. At the same time, Greece too, accused Turkey of developing nuclear weapons.
In 1982, a Nuclear Energy Authority was established in Turkey. In 1983, Turkey initiated a renewed effort toward the establishment of an energy reactor. The idea was to have three reactors built according to the BOT model with the foreign contractor operating the reactor over a period of 15 years. However, this effort never materialized, for various reasons, notably the concerns of western countries that Turkey would use these reactors to develop nuclear weapons.
In the late 1980s, concerns about the possibility that Turkey was developing nuclear weapons increased owing to the nuclear cooperation agreement Turkey had signed with Argentina in 1988. Turkey intended to purchase an Argos PWR type reactor developed in Argentina, in the previous year. Both countries were looking into other activities, including the mining of uranium and reactors for the production of nuclear fuel. Argentina's objective was to use Turkey as a model client with the intention of marketing reactors of that type in our region. Turkey, for its part, wanted to acquire from Argentina another reactor – type CAREM-25.
CAREM-25 was a 25-megawatt reactor and regarded as "too small to produce energy and too large for research purposes, but suitable for the production of plutonium", by senior Turkish official stated at the time. According to the agreement, Turkey should have financed two such reactors, one to be erected in Turkey and the other in Argentina. This was one of the biggest causes of USA concern which is the Turkey's possible cooperation with Pakistan on nuclear smuggling over this.