He was an intelligence and strategic affairs correspondent for the Haaretz newspaper, and in 2013 he joined The Jerusalem Post and its Hebrew sister paper Maariv in a similar, more analytical role covering also military issues.

He wrote 10 non-fiction books on the Israeli Intelligence Community, security, terrorism and nuclear issues which were published in more than 40 countries in 15 languages.

One of his books, Every Spy a Prince, co-authored with former CBS News reporter Dan Raviv, was a New York Times best-seller for 12 weeks.

[5] In 2020, US President Donald Trump retweeted Melman's account of the killing of Mohsen Fakhrizadeh, head of the nuclear program of Iran.

[8] While supporting the peace process with the Palestinians, Melman believes that Israel must retain its strong military capabilities, including its nuclear deterrence.

[10] In 2003 together with a few other members of the ICIJ investigative team he has received a special award for their coverage "Making a Killing: The Business of War", a project of 11 feature articles on worldwide arms dealers, oil and diamond merchants in Third World countries.

In 2007 participated together with ICIJ reporters Michael Bilton, Prangtip Daorueng, Ignacio Gomez, Andreas Harsono, Alain Lallemand, Mutegi Njau, Paul Radu, Gerardo Reyes and Leo Sisti in an investigatory project Collateral Damage: Human Rights and Military Aid After 9/11.