A study conducted by the Oxford Research Group has concluded that the war in Iraq could last for decades.
The study said al Qaeda could keep the US tied up in Iraq for many years.
And Britain would only withdraw troops in the "highly unlikely" event of a break with Washington.
The Oxford Research Group which studied the latest events in Iraq, said the war was still in its early stages and was likely to last for decades.
The group says the occupation has been a "gift" to al Qaeda. The terrorist group has won recruits by portraying the US presence as a neo-Christian occupation of a major Islamic state.
Furthermore the report says that ensuring Iraqi security and maintaining a friendly government in Baghdad is an essential part of US security policy even if it requires a permanent military presence.
It says long-term access to Persian Gulf oil is essential to the US because of its increasing dependence on imported oil.
The report warns that a US withdrawal would be a "foreign policy disaster greater than the retreat from Vietnam".
"Given that the al Qaeda movement and its affiliates are seeking to achieve their aims over a period of decades rather than years, the probability is that, short of major political changes in the USA, the Iraq war might well be measured over a similar time span," it concludes.
PA