Turkey disclosed to Iranian intelligence the identity of up to ten Iranians who were allegedly spying on Tehran for Israel, journalist David Ignatius wrote on Thursday.According to Ignatius, Ankara's decision to expose the alleged Mossad informants came early last year as Turkish-Israeli relations continued to deteriorate following the 2010 Mavi Marmara incident.Ignatius cites sources as saying the Turkish action was a "significant" loss of intelligence for Israel, and "an effort to slap the Israelis." According to Ignatius, the Mossad was running part of its Iranian spy network through Turkey. The Turkish intelligence conducts aggressive surveillance inside its borders, which enabled it to monitor covert Israeli-Iranian meetings.Israel, Ignatius writes, ties Turkish intelligence chief Hakan Fidan to the Iranian intelligence. Despite that, Israel's ally the US continued dealing with Fidan on sensitive matters and Washington did not protest the Turkish action directly to Ankara.Fidan, who is a key adviser to Erdogan, has "rattled" key allies in the past by revealing sensitive information collected by Israel and the US to Iran, according to Ignatius.The decision to reveal the identities of the spies was personally approved by Turkish Prime Minister Recep Tayyip Erdogan, according to Ignatius. The columnist speculated that the premier's move may explain Prime Minister Binyamin Netanyahu's initial refusal to apologize to Erdogan, who has made it a point to assume a more adversarial position toward Israel, in hopes of boosting Turkey's regional standing, over the deaths of Turkish civilians on the Mavi Marmara.Ignatius cited assessments by American intelligence officials who believe that the Mossad was taken by surprise considering that the Israeli spy agency had to that point enjoyed a 50-year working relationship with Turkey.