Mr. Bush and first lady Laura Bush received a royal welcome at Heathrow Airport where they were greeted on the tarmac by Prince Charles, before helicoptering to Buckingham Palace.
But CBS News Chief White House Correspondent John Roberts reports that some British lawmakers would rather send Mr. Bush back home, saying that with Iraq still a mess this is no time for a King-size photo op.
"The sense of outrage in this country stems from the fact that our prime minister has encouraged this visit to go ahead. Why on earth, as someone said to me the other day, are we being subjected to the dumb and dumber show across London when the situation is seemingly getting worse by the day," said Member of Parliament Glenda Jackson.
The pageantry of this visit contrasts sharply with protests that kicked off as opponents of the Iraq war vowed to put 100,000 people on the streets later this week.
"I think he is a disgrace. I think he is a disgrace to the American people and these demonstrations are in solidarity with the American people. We are not anti-American; we are anti-Bush," said one protestor.
That strong opposition – and threats of terrorist attack – have prompted unprecedented precautions here. Heathrow Airport was swept for missiles and bombs before the president arrived, and security concerns nixed the traditional open carriage ride other world leaders have taken with the Queen.
But not all Britons are against the visit. In fact, there is strong support for it and the overwhelming belief here that America is a force for good.
President Bush hopes to build on that sentiment this week and give a boost to the battered prime minister who stood by his side. But, says political commentator Peter Ridell, that may do more harm than good for Mr. Bush's staunchest ally, Prime Minister Tony Blair.
"The warmer George Bush talks about Tony Blair the more embarrassing it is for Tony Blair, because in Britain, he's accused of being Bush's 'poodle'," Ridell says.
President Bush will insist this week that in Iraq he and Blair were defending the ideals of democracy that the British people hold so dearly. In a speech Wednesday at Whitehall Palace, Mr. Bush planned to argue that war is the correct path when all other means have failed, a senior administration official told reporters flying here with the president on Air Force One.
"History has shown that there are times when countries must use force to defend the peace and to defend values," Mr. Bush was to say.
But Mr. Bush did not plan to define which values he was referring to, nor when, exactly, it is necessary to go to war.
The remarks, billed by White House aides as a major foreign policy address, also were to reiterate Mr. Bush's call for countries across the globe, particularly in the Middle East, to embrace democracy.
But the president faced deep opposition here. One protester used a bullhorn to bark a stream of anti-Bush and anti-Tony Blair invective at Parliament Square Tuesday afternoon, comparing the two leaders to Hitler. "How can you be bombing babies, Mr. Bush and Mr. Blair? It is not Christian, it is blasphemy!"
Yet a new poll contained good news for President Bush.
Forty-three percent of Britons questioned in an ICM survey said Bush should visit the country, while 36 percent said he should not. About 62 percent agreed that America was "generally speaking, a force for good," while 15 percent believed it was "an evil empire."
Mr. Bush and his aides are fond of saying they do not pay attention to polls, but the senior administration official who addressed reporters on Mr. Bush's plane cited the new survey as evidence of strong ties between the two countries.