EUROPE is mired in debt and recession. Financial markets have hit violent ups and downs on fears that US stimulus efforts may soon be scaled back. Japan is finally looking up after years of stagnation, but it remains an open question if the recovery will stick.

That's the global economy that will confront the heads of the Group of Eight leading economies as they gather today and tomorrow for their annual summit in Northern Ireland.

British Prime Minister David Cameron will serve as summit host for US President Barack Obama and the leaders of Germany, Italy, Canada, France, Japan and Russia. At the top of the agenda is new cooperation to fight tax evasion and increase transparency among governments. Also on the table will be how much help to give to rebels in Syria, and a push for lower trade barriers between the US and the European Union.

On the sidelines and over dinner, it's expected that the discussions will broaden to include the election results in Iran and data protection, following revelations about a US counterterror surveillance program.

As always, the summit takes place under heavy security, guarded by 8,000 police backed by water cannon. The venue itself is surrounded by extensive security fences, and on three sides by water. There's only one access road to the closest town, Enniskillen, some 8 kilometers away.

While its peace process has been hailed worldwide as a success story, Northern Ireland remains a society troubled by deep-seated divisions between Catholics and Protestants. Officials have said trouble away from the summit site can't be ruled out. Additionally, thousands of anti-capitalist and labor union protesters are expected to march from the town to the summit fence today.

Since last year's G8 meeting at Camp David in the US, there has been a modest economic upswing throughout the developed world and prospects are brighter after five years of turbulence and recession. Yet despite progress, the economic outlook remains uncertain.

Chief among the question marks: When will the US Federal Reserve begin to curtail its extraordinary stimulus, which has supported the recovery in the US and helped send markets around the world to new peaks? Global stock and bond markets have whipsawed since May 23, when US Fed Chairman Ben Bernanke said the US central bank might slow its drive to keep long-term borrowing costs low in the coming few months.

If Europe is the weak link and Asia the strongest, then the US and Canadian economies are squarely in the middle. The two countries are experiencing steady, if not spectacular, economic growth and job gains.

In the US, the once-battered housing sector has been recovering for the past year. Home sales have reached three-year highs. And prices have jumped this spring by the most in seven years. That has encouraged builders to start work on more homes.

The unemployment rate has fallen to 7.6 percent from 8.2 percent a year earlier.

For all the G8 participants, the most unsettling shift is the possible end of massive monetary stimulus from the Fed - a factor beyond their immediate control.

The Fed's injections of money into the economy through bond purchases - known as quantitative easing - had helped send markets soaring.

Now it's not clear which way markets will head.