In a recent article by Marcia S. Smith at spacepolicyonline [spacepolicyonline.com] we learn that:
NASA is denying all travel for NASA employees and contractors to the Committee on Space Research (COSPAR) conference to be held in Istanbul, Turkey beginning just five weeks from now. The reason: security. COSPAR President Lennard Fisk worries not only about the impact on COSPAR, but the messages NASA is sending about its commitment to leadership in space science and its resolve to not let terrorism be rewarded by changing what we do.
COSPAR [wikipedia.org] is the Committee on Space Research. On even-numbered years (2016, 2014...) COSPAR holds a Scientific Assembly [tubitak.gov.tr], the 41st of which will be in Istanbul this year.
In a statement provided to SpacePolicyOnline.com, COSPAR President Len Fisk expressed his deep concerns:
NASA has cancelled all travel of NASA civil servants and contractors to the COSPAR-2016 meeting to be held in Istanbul on 30 July - 7 August. And by doing so it demonstrated that it has no intention of exerting strategic leadership in the world, and that terrorism should be rewarded. The leaders of all the major space programs will gather in Istanbul to discuss among other topics, the future of human space exploration, but NASA will be absent. The major scientists of the world will gather in Istanbul, to share the results of their research, to plan future projects, to promote international cooperation in space science, but NASA civil servants and NASA sponsored contractors will be absent. And for what reason: a misguided assumption that Istanbul is more dangerous than Paris, or Brussels, or Orlando, Florida, or for that matter Israel and Jordan where NASA Administrator Charles Bolden recently visited. Terrorism is rewarded if it causes us to cease to pursue that which is important, or for that matter our daily lives. [From Marcia S. Smith's article]
The US State Department currently has a travel warning for Turkey [state.gov].