The Bush White House considered Tony Blair "completely naive" in dealing with Sinn Fein especially on the issue of Sinn Fein providing policing in nationalist areas a new book alleges.

In her new book "Peace without consensus - Power sharing politics in Northern Ireland" Mary Alice Clancy also quotes an Irish government official making similar  damning comments about Blair and his main advisor on Irish issues Jonathan Powell.

"I'm generally very supportive of Powell and Blair but that was one issue on which I was astonished because I think it showed complete naivete," the official said.

The book also  reveals that Bush's special envoy to Northern Ireland, Mitchell Reiss, never accepted  claims by Gerry Adams and Martin McGuinness that they were feeling  intense  internal pressure from  the IRA in the the two years before the St Andrews agreement.

Reiss saw  those claims as "a ploy and a bluff" to wring  more concessions from the British the book claims.

 However, both Powell and  Blair believed  Adams and McGuinness even though British security services were telling Reiss that no such threat existed.

White House staff and the unnamed Irish official were especially  upset  that Blair and  Powell at one point  were prepared to allow Sinn Féin to run policing in nationalist areas says the book.

That  willingness  almost brought down the historic deal at St Andrews in 2006 that led to the establishment of the current power-sharing government, senior White House staff told the author.

The Bush administration regarded  Blair's  attitude to ongoing IRA crimes and violence as "absolutely insane", historian Mary-Alice Clancy's book claims.

One senior, unnamed member of the Bush administration describes the Sinn Féin proposal on self policing in the run up to St Andrews as "autonomous thugocracies" and a "scandal".

The book claims that Reiss' ban on Sinn Féin fundraising in the US following the murder by IRA members of Robert McCartney had the full support of the British security services even though the Northern Ireland Office opposed the ban.