According to Yossi Melman, Cohen headed the European section of Tzomet, Mossad's human intelligence-gathering branch until 2005, when he replaced Mossad Officer N as overall head of Tzomet. Melman noted that although Cohen was a skilled collection agent, doubt had been cast on the appointment.
- Some call Y. "a man of all seasons," and note that he abandoned an overseas posting without completing his mission in order to join a high-tech startup headed by a former Mossad man a few years ago, only to return to the Mossad later on.
Cohen was appointed deputy director of Mossad in September 2011, making him a potential successor to director Tamir Pardo. Journalist Ronen Bergman said of him:
- Y. who is in his 50s, is considered a "home grown" appointment, having spent his entire career in the intelligence field in the Mossad.
- The newly appointed deputy is also considered to be exceptionally handsome and is known within the Intelligence Community as "the model."
- Barak Ravid, The odd appointment of Netanyahu's new national security adviser, Haaretz, 22 October 2013.
- Herb Keinon, PM names deputy Mossad head as new National Security council chief, Jerusalem Post, 21 August 2013.
- Yossi Melman, Returning the Mossad to its basics, Haaretz, 15 November 2005.
- Yossi Melman and Dan Raviv, Veteran Spy-Runner Moves from Mossad to be Netanyahu’s Chief Advisor on National Security — Iran Options Are a Key Focus, Spies Against Armageddon, 21 August 2013.
- Ronen Bergman, Mossad chief names new deputy, ynetnews.com, 5 June 2011.