Answer: When the US government says so.
When the Mujahedeen in Afghanistan were assassinating members of their government and the Russian troops dispatched to support it, they were, in Washington’s view, freedom fighters, even as their enemies branded them terrorists.
When they turned against an Afghan government imposed by the United States or revolted against a US invasion, they were once again branded terrorists.
When armed groups battling Khadafy’s government were supported by NATO, they were called freedom fighters. When some recently and allegedly turned violently against the United States, which is now dominating Libyan politics, they are once again castigated as terrorists.
And now, the United States Government through a decision by Secretary of State Hillary Clinton has decided that the Iranian group Mujahedeen Khalq, or People’s Mujahedeen, that had been on the US State Department’s terrorist list for years, has now been taken off the list.… Read the rest