While many of us were focused on the Boston bombings, Venezuela’s dubious elections and North Korea’s war noises in recent weeks, the world’s biggest nations took a potentially historic step — they launched a system to detect secret offshore bank accounts.

At an April 19 meeting in Washington, D.C., the G-20 group of nations, the club of the world’s largest economies, announced an agreement to start an “automatic exchange” of information on bank accounts of people who may be evading taxes or trying to hide dirty money abroad.

At the same time, the G-20 agreed to put new pressure on tax havens to lift their bank secrecy laws. The G-20 cited 14 nations, including Switzerland, Panama, Guatemala and Trinidad and Tobago, as countries that don’t meet international standards of tax information exchange.

Some money laundering experts say that the G-20 agreement could also help prevent government corruption scandals, such as the recent reports that Argentina’s late President Nestor Kirchner’s aides may have deposited more than $65 million in foreign tax havens.

“There are a lot of corrupt politicians around the world who are nervous about the discovery of their hidden accounts, and they have reason to be concerned,” says Charles Intriago, head of the Association of Certified Financial Crime Specialists. “This may be the beginning of the end of bank secrecy havens.”

According to Intriago, the G-20 agreement has a good chance of succeeding because the United States and European governments, which make up the core of the G-20, are financially strapped and desperately need to increase their tax collections.

That means they will likely go after their tax evaders with unprecedented zeal, he says.

The G-20 deal, prompted by an ongoing campaign against tax havens by the Organization of Economic Cooperation and Development, came only six days after France, Germany, Italy, Spain and the United Kingdom announced they would sign an agreement to identify tax evasion within and outside their borders.

The European agreement, in turn, follows the steps of a 2010 U.S. law — the Foreign Accounts Tax Compliance Act (FATCA) — that requires foreign banks to report accounts of U.S. residents starting on Jan. 1, 2014.

U.S. officials say that, for the time being, Washington will only exchange information with countries with which it has signed treaties to that effect, such as Mexico. It will not exchange tax data with countries such as Argentina or Venezuela that either have not signed tax treaties with Washington, or that are known to use tax information for political motives.

According to the Tax Justice Network, a British-based non-government group, there is more than $9.4 trillion deposited in tax havens around the world, including $1.1 trillion from wealthy Chinese, $520 billion from Brazilians, $417 billion from Mexicans, $406 billion from Venezuelans and $399 billion from Argentines.

In some cases, such as Venezuela’s, deposits in tax havens exceed the country’s gross domestic product.

Asked about the G-20 agreement, Moisés Cohen, a Panamanian banker and former head of Panama’s Bankers Association, told me that Panama is not a tax haven, because tax havens by definition do not tax deposits. Panama does.

And Panama is taking concrete steps that will soon get it off the list of countries that don’t meet international standards of tax information exchanges, he added.

Other bankers caution that, while the G-20 moves may help trace the funds of tax evaders and corrupt politicians, the proposed global cooperation could hurt legitimate business people who deposit their savings abroad to protect themselves against repressive governments or economic instability.

It’s hard to blame Argentines for putting their money in offshore accounts, when their bank deposits were seized by the government in 2001. And it’s hard to blame Venezuelans for sending their money abroad when the government is selectively punishing the opposition and confiscating companies at its whim, they say.

My opinion: The G-20 agreement is a step forward, but it’s mostly a statement of good intentions. I read some parts of it, and it has more holes than a Swiss cheese (no pun intended).

It says the G-20 countries will urge countries to automatically exchange tax information with their treaty partners “as appropriate” and “taking into account country-specific characteristics.” That leaves a lot of room for maneuvering.

Still, the G-20 move starts a new process that will eventually make it harder for people to hide money offshore. It’s an issue that is not making headlines, but should.

It deserves a much greater public discussion, both to ensure the protection of legitimate depositors who live in unstable countries and to advance the fight against tax evaders and corrupt politicians who hide their money abroad.