Axis of forgery

Tucked away in this Guardian article from 2004:

This week, reports warned that counterfeiters in North Korea are gearing up to make dodgy euros...
Beyond North Korea, Syria and Iran are known to indulge in highly advanced counterfeiting.

This mirror of a 2002 piece from Christian Science Monitor explains part of the motivation:

The last big wave of overseas counterfeiting was the high-quality copies of US $100 bills that flooded several continents in the 1990s, apparently originating in Iran and North Korea. These fakes had the dual aim of profit for the producers and distributors and destabilization of the US economy by attacking the world's favorite money, the almighty dollar.

Destabiliziation of the US economy by debasing its currency squarely fits within the framework of Fourth-Generation Warfare (4GW). Syria, Iran, and North Korea are definitely players on this front. I consider it highly probably that they've traded counterfeiting technology, given that other technology has been transferred as well.

According to Stacy Keach via PBS:

Over $360 million in counterfeit notes were confiscated in 1995 alone. Millions, perhaps billions more, went undetected...
Nearly two-thirds of US cash is overseas, so counterfeiting is a worldwide problem. Where demand for dollars is strong, such as in Russia, there has been a surge in high-quality counterfeiting. In 1993 alone, the amount confiscated abroad grew 300%. The most popular target of international counterfeiters is the $100 bill. These counterfeit hundreds support arms purchases, the drug trade, and terrorist activity. There are even suggestions that counterfeiting is being used as a calculated attack on the nation. A Republican congressional taskforce issued strong charges with this 1992 report, warning: "Evidence has recently come to light that the governments of Iran and Syria are actively engaged in economic warfare against the United States through the production and dissemination of high-quality counterfeit dollar bills." The report describes a conspiracy arising from the ruins of the war between Iran and Iraq. Short of hard currency, the Iranian government allegedly launched counterfeiting operations to help the country rebuild. The Iranian government dismisses these charges. But there are counterfeits of such high quality found in the Middle East, they're called "Supernotes."

Thanks to high oil prices, Iran is not lacking for hard currency these days. Given the appeal of economic warfare and illicit funding, said counterfeiting is not likely to stop.