Turkish Navy, constitutes the naval warfare service branch of the Turkish Armed Forces. The Turkish Navy maintains several Marines and Special Operations units. The Amphibious Marines Brigade (Amfibi Deniz Piyade Tugayı) based in Foça near İzmir consists of 4,500 men, three amphibious battalions, an MBT battalion, an artillery battalion, a support battalion and other company-sized units. The Su Altı Taarruz (S.A.T. – Underwater Attack) is dedicated to missions including the acquisition of military intelligence, amphibious assault, counter-terrorism and VIP protection; while the Su Altı Savunma (S.A.S. – Underwater Defense) is dedicated to coastal defense operations (such as clearing mines or unexploded torpedoes) and disabling enemy vessels or weapons with underwater operations; as well as counter-terrorism and VIP protection missions. Air Force The Turkish Air Force is the aerial warfare service branch of the Turkish Armed Forces. It is primarily responsible for the protection and sovereignty of Turkish airspace but also provides air-power to the other service branches. Turkey is one of five NATO member states which are part of the nuclear sharing policy of the alliance, together with Belgium, Germany, Italy, and the Netherlands. A total of 90 B61 nuclear bombs are hosted at the Incirlik Air Base, 40 of which are allocated for use by the Turkish Air Force in case of a nuclear conflict, but their use requires the approval of NATO. The Air Force took part in the Operation Deliberate Force of 1995 and Operation Allied Force of 1999, and later participated in the United Nations peacekeeping mission in Bosnia-Herzegovina, employing two squadrons (one in the Ghedi fighter wing, and after 2000 one in the Aviano fighter wing.) They returned to Turkey in 2001. In 2006, 4 Turkish F-16 fighter jets were deployed for NATO's Baltic Air Policing operation. Military bases and soldiers stationed abroad As of February 2021, Turkey has at least over 60,000+ military personnel stationed outside its territory. The only military base stationed permanently abroad, regardless of the organizations that are members of Turkey, which has been temporarily holding troops several times abroad due to its responsibilities arising from many international political members, particularly NATO membership, is the Cyprus Turkish Peace Force Command. The military bases of the Turkish Armed Forces in Qatar, Syria, Somalia and Bashiqa, among an unknown amount of other bases internationally, are currently active. It was announced in 2017 that Turkey would start working on establishing a research base in