Every so often, some executive or politician asks why oh why does the world insist on using US dollars for trading oil or aluminium or coffee or some other chunk of the world that gets mined or grown or manufactured and then bought and sold.

And, briefly, some analysts and traders then imagine trading Brent crude in euros or gold in yuan, and then they get on with buying and selling comestibles and raw materials using Uncle Sam’s currency.

The dollar’s status as the world’s reserve currency of choice is pretty much a given. There’s a chance, though, that recent events might just start to erode the greenback’s dominance.

MegaFon, the Russian telecoms firms owned by Alisher Usmanov, the nation’s richest man, has started shifting its cash away from dollars and euros as the US and Europe accelerate sanctions against Russian President Vladimir Putin and his empire. Chief financial officer Gevork Vermishyan told Bloomberg’s Ilya Khrennikov that MegaFon had shifted about 40 percent of its money into the Hong Kong dollar, which is pegged to the US currency.

For Russian companies, it’s much safer from the standpoint of sanctions.

The dollar’s dominance in global foreign exchange reserves has been slowly slipping, and has declined to about 60 percent from more than 70 percent at the beginning of the previous decade, according to figures from the International Monetary Fund. Last month, as European banks mulled the implications of the $9 billion (R96bn) fine US authorities imposed on BNP Paribas for doing dollar business with nations Washington categorised as pariahs, HSBC chairman Douglas Flint advised members of the Institute of International Finance’s board to study a book, Treasury’s War: The Unleashing of a New Era of Financial Warfare, by Juan Zarate, a former US deputy national security adviser.

The tome, published in September last year, describes the playbook the US has used to wield its financial weaponry against rogue states, tracking and seizing assets through the global banking network. Among its revelations – I’m about three quarters of the way through its 577 electronic pages – is an attempt by Russia in 2008 to persuade China to join forces with it and dump billions of dollars of Fannie Mae and Freddie Mac debt into the market, which would have forced the US to spend “massive sums to keep Fannie Mae and Freddie Mac alive”, Zarate writes.

China declined to participate; Zarate calls the episode “a glimpse into a new age of geo-economic competition”.

Last month Zarate, who is now with the Centre for Strategic and International Studies in Washington, acknowledged the risks of wielding the dollar in financial warfare. Have we reached a tipping point, and are we accelerating the de-Americanisation of the financial system?

The US needs to be wary of what my colleague Leonid Bershidsky has dubbed “weaponising the dollar.” Who knows how many other Russian companies are pre-emptively starting to shun the US currency – just in case? – Bloomberg