What comes out of the G-20 Summit will have far-reaching repercussions for global economic health.
Between now and then, however, there are differences among the US, the UK and Europe, not to mention the developing nations, that will have to be bridged.
Three broad issues have emerged so far - the need to raise the capital of the International Monetary Fund, tighter financial market regulation and concerted efforts worldwide to stimulate growth.
The US would like the IMF to fortify its war chest so that it can come to the assistance of countries facing balance-of-payments crises. The US has proposed some US$750 billion (Bt27.3 trillion) for the IMF, while Europe is aiming for a small figure of about $500 billion.
Anyway, the international agency is definitely going to need enough firepower to combat the crises, unseen since the Great Depression in the 1930s.
The G-2o meeting of finance ministers over the weekend agreed formally to boost the lending of the IMF. Who will pay the bill? Its communique did not spell out the exact figure. This question will have to be sorted out by the leadership summit.
Before the crisis, the IMF was very unpopular with the US Congress, which did not want to waste taxpayer's money to finance the IMF.
Now the situation is completely different. Many emerging economies are facing capital outflows and need IMF funding. They liberalised their economies about a decade ago and have moved into an over-investment and over-consumption mode. The party is now over, and many, particularly from the Eastern European countries, are now turning to the IMF for help.
The Europeans are now feeling uneasy with the unfettered liberalisation of financial institutions. They now would like to tame the banks, financial institutions and hedge funds or other shadow banks, which played a big part in the financial bubbles and their collapse.
Banks have become globalised. Toxic instruments issued by US institutions have spread worldwide. The failure of one bank could infect the whole global system.
The fall of Lehman Brothers last year is a case in point. After its collapse, the credit market came to a grinding halt because of the financial linkages. Moreover, investors were afraid that more banks were about to fold.
US and European banks are now sitting on mountains of bad loans and toxic assets. They are not sure how to carve them out because doing so would wipe out their capital. They are incurring huge losses.
So far the US, UK and other governments have injected taxpayer's money to keep the banking systems alive. They would like the financial system to return to normal as soon as possible. But the problem is so huge that tougher measures will be needed.
It remains unclear how the G-20 Summit will agree on global stimulus measures. Larry Summers, the chief economic adviser to the Obama administration, has recently called for a global concerted effort to stimulate growth via government spending.
Although governments are now pumping out fiscal measures to boost growth, they have different views on sharing the burden.
France and Germany are more conservative on this front. While the US stimulus package is worth around $800 billion, which represents almost 6 per cent of gross domestic product, Germany is about to spend its stimulus package set at about 1.5 per cent of GDP. France is going to spend a similar amount, while the UK's package is equivalent to only 1 per cent of GDP.
But Germany and France are opposed to US calls for new pump-priming, instead favouring tougher regulation to tackle the crisis.
French Finance Minister Christine Lagarde said she was "delighted" that the G20 was closer to agreeing on tighter regulation of markets. Last week German Chancellor Angela Merkel and French President Nicolas Sarkozy said at a joint press conference in Berlin that "Germany and France will send a common signal at this summit".
That signal, in a direct rebuttal to US calls for more spending, stresses that "spending even more is not the issue, the issue is to put in place a regulatory system to prevent the economic catastrophe that the world is experiencing from being repeated."
European countries insisted that their stimulus packages were already enough and the more important thing was to deliver such packages. And they had regulatory measures in place to protect against similar crises erupting out of Anglo-Saxon capitalism.
China is watching its investment in the US with a sense of alarm. It is afraid its investment would produce losses. It has called on the US to guarantee its investment. China, still, goes ahead to announce stimulus packages to boost growth and to keep the growth rate above 6 per cent.
Abhisit Vejjajiva, the Thai prime minister, will join the G-20 Summit for the first time as an observer. He is likely to highlight the crisis as originating from the developed nations.
He would also call for global efforts to stabilise and reform the financial system so that we would not confront this kind of crisis again. Thailand is also playing its part in boosting growth via government spending.
Looking ahead, the G-20 Summit will be a high point of high expectations. Business leaders will watch the outcome closely. They are also questioning whether the G-20 has enough resources and political will to tackle the crisis.
If the G-20 Summit fails to come up with measures to boost confidence, the global economy will further head into a downward spiral.