Iraq faces the distinct possibility of collapse and fragmentation, UK foreign policy think tank Chatham House says.
Its report says the Iraqi government is now largely powerless and irrelevant in many parts of the country.
It warns there is not one war but many local civil wars, and urges a major change in US and British strategy, such as consulting Iraq’s neighbours more.
The Chatham House report, written by Gareth Stansfield, a Middle East expert, is unremittingly bleak, says BBC diplomatic correspondent James Robbins.
Mr Stansfield argues that the break-up of Iraq is becoming increasingly likely.
In large parts of the country, the Iraqi government is powerless, he says, as rival factions struggle for local supremacy.
The briefing paper, entitled Accepting Realities in Iraq, says: “There is not ‘a’ civil war in Iraq, but many civil wars and insurgencies involving a number of communities and organisations struggling for power.”