Six months after their last crisis summit, the leaders of the world's major economies can at least point to progress in their battle to prevent wealthy tax-dodgers spiriting money away to tax havens.
While still far apart in many areas of financial regulation, the G20 group will meet this week in Pittsburgh after successfully convincing some formerly secretive jurisdictions to share information on offshore accounts.
"The world has completely changed," said Alain Maillot, a French tax lawyer, perhaps overstating the case, but reflecting the mood in a sector surprised by the speed of recent reforms in once stubborn financial centres.
The last time the G20 met, in April in London, the leaders agreed to block the "black holes" in the financial system, arguing that the ease with which some market players hide their profits contributes to instability.
New lists of "non-cooperative" countries were published, sanctions were threatened and several places -- including large financial centres such as Belgium and Luxembourg -- did what was needed to get off the "grey list".
Top tier banking destinations like Switzerland and Singapore are now also working to put themselves in the clear, further narrowing the number of places that firms and individuals can go to hide their cash from the tax man.
"Sometimes decisions taken by leaders are not followed up in practice, but in this case the results have been fairly extraordinary," Pascal Saint-Amans of the Organization for Economic Co-operation and Development (OECD) said.
If countries want to stay off OECD black and grey lists of tax havens, they can no longer hide behind their own banking secrecy laws in order to deny tax investigators access to account records.
This principle has already partly lifted the veil on Switzerland's banks: The United States has managed to get the names of 4,450 of its citizens with deposits in UBS and France boasts of having tracked down 3,000.
So will the leaders meeting this week in Pittsburgh be able to claim that the era of banking secrecy is over? Not quite, analysts warn.
While many jurisdictions have signalled their willingness to cooperate with specific inquiries, systems for the automatic exchange of information between national authorities have yet to be put in place.
Investigators seeking information on citizens' accounts abroad still have to provide prima facie evidence of tax evasion in individual cases. Switzerland, for example, insists on knowing the name of the bank involved.
"The tax information exchange agreements are not very effective," said Richard Murphy of Tax Research, a British accountancy firm that advises governments, charities and pressure groups.
"We want to know data will really be exchanged... and we must be sure that automatic information exchange is created to provide the data that is the 'smoking gun' to make these agreements work."
Global automatic systems to share account information would make it harder to evade tax or launder ill-gotten gains, even if national tax officials don't have enough evidence to launch a legal bid for information.
"Information exchange only after a request leaves too much leeway to tax havens," said Maylis Labusquiere, of the development charity Oxfam, which will lobby the G20 for a tougher crackdown.
Campaigners accuse some jurisdictions of paying lip service to the new rules while seeking ways around them.
For example, governments are supposed to demonstrate good intent by signing bilateral information sharing deals with at least 12 others. Monaco has done so, but seven of its 12 partners are fellow tax havens.
In order to oversee the ongoing campaign, 30 countries have come together to form a task force to identify non-cooperative tax havens and punish them.
The head of the group, France's chief offshore tax hunter Francois d'Aubert, says he hopes the G20 summit will confirm that backsliders could face sanctions from as early as March next year.
"It's a question of credibility," he said.
Others, including Raymond Baker of Global Financial Integrity Program, a US-based pressure group, would like governments to turn the screws on multinational firms that hold accounts in offshore centres.
"These issues are in danger of being diluted and the momentum for effective and meaningful change may be lost," he warned.
One key factor, however, adds strength to the campaigners' cause. With stimulus spending driving up massive national deficits, many governments are determined to finally recoup all the tax due to them to plug the holes.