The Russian President's announcement that "unfriendly states" (including Germany) should in future only be able to buy gas for rubles and no longer for foreign currencies such as the euro or dollar has also triggered speculation among experts.

What is Vladimir Putin aiming for with this decision?

Even after a day it's not entirely clear;

different interpretations, which are not mutually exclusive, are possible.

The message could be aimed at one's own country: it is intended to generate confidence in the value of one's own currency.

The message is also addressed to the “unfriendly countries”.

It is to be interpreted as an attempt to undermine the sanctions regime and stir up discord among the "unfriendly".

Since there are not too many rubles available on the Western foreign exchange markets, sooner or later the West will have to get rubles in Moscow by first selling euros or dollars there for rubles, which it then uses to pay for gas supplies.

Even if the gas is paid for in rubles, western foreign currency flows to Moscow.

In this case, however, there will be demand from the West for the ruble, which could do the exchange rate of the Russian currency good, at least in the short term.

What is important, however, is that the West would first have to buy its rubles in Moscow.

But if only the central bank were to offer itself as a seller, the West would undermine the sanctions it imposed on the central bank by buying the ruble.

In addition, the central bank in Moscow could stop the exchange of rubles for Western currency at any time on Putin's instructions - and then the West would no longer be able to pay for the gas, even though its pockets are well filled with euros and dollars.

The West should reject this manoeuvre, which can be viewed either as a clever move or as an act of desperation.

And as an additional argument to take the initiative on the issue of energy sanctions - even if Putin will hope that the skeptics in Berlin will continue to shy away from it.