As the euro teeters on the brink of collapse, and the global economy faces unprecedented severe weather warnings, recovering unpaid tax is a higher priority than ever for countries feeling the financial pain.
Here in the UK, the government has earmarked additional funding to ensure that no stone is left unturned in its determination to stamp out tax evasion and avoidance. Recent estimates from HMRC (Sept 2011) suggest that the Tax Gap - that is, the difference between tax collected compared with that owed - could be around £35 billion: a serious figure at the best of times, let alone in a period of severe financial austerity.
The USA is also closing the net on the billions of dollars that the IRS believes to be held in offshore accounts, as shown in recent talks between the US and Switzerland over a possible tax treaty.
One of the most valuable assets sought by the tax authorities, however, is data. International agreements are increasingly focused on disclosure of information as a means of recovering past unpaid taxes, encouraging future compliance and deterring would-be evaders from hiding their money in the first place on the basis "be sure your sins will find you out."
Resistance has been strong - the recent deals agreed between the UK and Switzerland, as well as between Germany and Switzerland, enable individuals to retain anonymity, but at the cost of a large one-off payment to cover past tax liabilities and a high annual withholding tax to settle on-going tax due. Clients who opt out of this withholding will, generally, have their details revealed to HMRC.
This has raised more than a few hackles within the European Commission, which regards such deals as going against its rules on data disclosure
However, in a bid to get the information they need, the authorities are increasingly targeting individual banks directly, rather than relying on blanket international agreements. The USA in particular is bringing criminal charges against banks which assist US citizens with tax evasion levying large fines and requiring the banks to reveal details of their clients.
Now that major banks have agreed to hand over client details, we are likely to see an acceleration in information sharing. The Swiss/UK Agreement imposes obligations on institutions to ensure their clients are tax compliant and in some circumstances enables information to be passed to the authorities.
Tax amnesties have also proved a valuable tool for tax authorities in the past, with measures such as Lichtenstein Disclosure Facility (LDF) encouraging non-compliant individuals to confess their sins - and pay back taxes and interest, but with reduced penalties.
Many countries are introducing legislation with extraterritorial effect which seeks to impose reporting requirements on individuals and institutions so the authorities can make sure that account holders are paying the tax they owe - on pain of severe financial penalties for non-compliance. The most high profile example is the USA's Foreign Account Tax Compliance Act (FATCA).
Other countries like Israel and France are imposing onerous reporting requirements on individuals with offshore funds, and the UK is also issuing tax returns to offshore trustees.
The effect of these measures is that people who fail to pay the taxes they owe are increasingly left with nowhere to hide. Even if the governments of tax havens are prepared to protect individuals, the banks themselves may be unable to escape investigation - or prevent information being stolen and leaked by an employee, as has happened recently.
Tension between the authorities and tax evaders is an age-old feud, but the storm currently brewing in the global financial markets is set to intensify the situation, with the stakes much higher on both sides.