The political landscape in Britain shifts this week with the rise of Gordon Brown to the premiership. For an event that has been anticipated for years, due to the long-standing political bargain between Mr. Brown and former Prime Minister Tony Blair, its contours are still widely debated here.

How will Mr. Brown's policies diverge from Mr. Blair's? Will he be an Atlanticist or an Europeanist? Will Mr. Brown's traditional socialist roots assert themselves? What will his ascendance do to the New Labor policies carefully pursued by Mr. Blair? And not least interesting of all, how will it affect the Conservative Party, which has been making great strides in voter popularity under the new leadership of David Cameron?

As Mr. Blair decamps for his new post as Middle East envoy, these two political leaders will square off against each other, Gordon Brown for Labor and David Cameron for the Conservatives.

Mr. Brown has already made a very surprising, but not actually very successful, opening move by inviting the leader of the Liberal Democrats to fill one or two of his cabinet posts, something unheard of in Britain since World War II. As speculation has it, Mr. Brown fears that Labor might lose the next general election to the resurgent Tories and will therefore need a coalition partner to hang on to power. A more sinister interpretation is that he is trying to eviscerate the Liberal Democrats in order to consolidate the left-leaning voting block under Labor. In any event, the plot got leaked to the press and exploded all over Britain's front pages, after which it fizzled.

In terms of defining what they stand for, the rhetoric of both Mr. Brown and Mr. Cameron is reaching for a new set of code words that have yet to be clearly defined. In doing so, both are paying homage to the genius of Tony Blair, a master of public relations. Mr. Brown talks constantly about an "aspirational" society and of "progressive change." Mr. Cameron talks of "our society, your life" and of the individual's right to control the government, not the other way around.

In scrutinizing their speeches, commentators here discern somewhat of the familiar outline of Labor vs. Tory philosophies, of a big-government approach vs. empowerment of the individual. However, both are clearly trying to reinvent their traditional political parties with rather confusing results. In many areas, they are in direct competition, as Mr. Cameron tries to make inroads on environmental and social issues that have for long been Labor's home turf. It is a strategy that is leaving many traditional Tory supporters and admirers of Lady Thatcher gagging.

Meanwhile, Mr. Brown is making an attempt at finding his own version of the "third way," as Mr. Blair called the mythical middle road between capitalism and socialism. As chancellor of the exchequer, or treasury secretary in American terms, he was largely responsible for the booming economy that kept the Blair government in power for the past 10 years. He is known to appreciate the power of the markets. On, the other hand, he also hails from a traditional socialist Scottish background, whose influence will be stronger now that he will hold the reins of power himself.

In terms of foreign policy, outlines are unclear as well. Mr. Cameron has made a point of distancing the British Tories from the Bush administration, though doing so with less abrasiveness than his predecessor Michael Howard. In any event, the closeness that existed between Mr. Blair and Mr. Bush caused Britain's Conservatives to stridently declare their independence from American leadership under a Republican president. There has been a lot of rhetoric from both Mr. Cameron and shadow Foreign Secretary William Hague about not being slavish followers of U.S. policy.

Meanwhile, Mr. Brown has not said a great deal on how he views the future of that relationship. While he has spoken of the continued importance of the transatlantic relationship, he has also repeatedly stated that his approach to Iraq and Afghanistan will be a "hearts and minds" approach - which suggests that we may soon see more British troops returning home.

How relations with the European Union shape up is equally important. Both are committed to engagement in Europe. Mr. Brown now seems to have accepted that the renegotiated and reduced constitutional treaty can be put through the British Parliament with out a referendum. At least the Tories are still firm in demanding that such a referendum take place.

From an American perspective, it is probably fair to say that, whoever wins, Tony Blair will continue to be sorely missed.

Helle Dale is director of the Douglas and Sarah Allison Center for Foreign Policy Studies at the Heritage Foundation.