Peace at Home, Peace in the World
In Turkish, the phrase "Yurtta sulh, cihanda sulh" - "Peace at Home, Peace in the World" - was first pronounced by Mustafa Kemal Atatürk on 20 April 1931 to the public during his tours of Anatolia. This stance was later integrated and implemented as the foreign policy of the Republic of Turkey.
The original full sentence was "Cumhuriyet Halk Fırkası'nın müstakar umumî siyasetini şu kısa cümle açıkça ifadeye kâfidir zannederim: Yurtta sulh, cihanda sulh için çalışıyoruz." This is translated into English as "To describe the stable and general diplomatic policy of the Republican People's Party, I think this short sentence is enough: We work for peace at home, peace in the world."
"Peace at Home, Peace in the World" is regarded as a central principle of the state administration and any state activities. It's not just regarded as one phrase, at the same time it's seen as a superior and integral objective.
"Peace at Home, Peace in the World" refers to peace and comfort at home to live in safety, on the other hand, international peace and security in the world. This principle is the fundamental basis of domestic and foreign policies.
This is one of the integrative principles of Ataturkism that explains any inconvenience you may have in the world can do damage to everyone. Because of this reason nations should not be indifferent to the problems of other nations. 
- "Synopsis of the Turkish Foreign Policy". mfa.gov.tr. Ministry of Foreign Affairs (Turkey). Archived from the original on July 20, 2016. Retrieved July 26, 2016.
- Atatürk’ün Tamim, Telgraf ve Beyannameleri, C. IV, (1917-1938), s. 549-552 http://www.kitapyurdu.com/kitap/default.asp?id=94901
- As translated by Mete Avcı Metheus