The United States is to withdraw virtually all its military personnel from Saudi Arabia - in a move US officials describe as being by mutual agreement with the Saudi authorities.
The decision ends a military presence that dates back to the Gulf war of 1991.
The US has thousands of troops in Saudi Arabia
At the end of that war, the US stationed some 5,000 military personnel in the kingdom to enforce a no-fly zone over southern Iraq.
During the recent war in Iraq their number doubled to 10,000.
US and Saudi officials have now decided the political costs of their presence outweigh their military usefulness.
It is not just radical Islamists like Osama Bin Laden who resent the US military presence on Saudi soil.
Many Saudis see it as proof of the country's subservience to America, and hence as an affront to their national pride.
The departure of US troops will boost the popularity of Saudi Arabia's de facto ruler, Crown Prince Abdullah.
He has long favoured their withdrawal, despite the reported misgivings of some of the most pro-American senior princes.
They may fear that military disengagement will lead to an overall downgrading of US-Saudi relations.
There have certainly been serious tensions between Riyadh and Washington over US support for Israeli Prime Minister Ariel Sharon - and the Saudis' alleged support of Islamic extremism.
But all the signs are that Crown Prince Abdullah's intention is to change the relationship, not end it.
Despite recent stresses and strains, America still needs Saudi oil and still wants the kingdom to play a moderating role in the Middle East and the Muslim world.
The Saudis, for their part, still want America as both a protector and an economic partner.
The two countries will remain allies, but they will not have the same relationship as in the past.