That is what hurts the Russian cause for Crimea. She signed a treaty recognizing the border of Ukraine when the Ukraine became independent and surrender the Soviet nuclear weapons on her soil to international disarmament teams. IMJHO Putin played out his cards and got the minimum out of the crisis, Crimea and the Russian naval base in Sevastopol. This minimum gain has roused EU (Germany did not abandon NATO despite all the business deals she has with Russia). The other thing that hurt Putin is China demanded for more access to Russian aviation technology as a precursor to buying Russian gas and oil. If Russia had invaded and taken the Russian dominated portions of Ukraine, even Obama will have no choice but to confront Russia by redeploying US assets from Asia to Europe and most of the NATO countries will rearm or move assets to Eastern Europe. IAW a mini arms race/Cold War. Russia stands to lose in the long run. Her small economy (2 trillion vs EU/US combine 30 trillion) will be consumed by arms race, plus the burden of feeding the Ukraine Russians, and worst make Russia more dependent on China. In a multipolar world, the first two powers fight, they lose. Nuclear weapons is the only thing Russia has but using it means they will lose. Russia tried dumping 23 billion in US T bills, only to see Belgium (supported by EU/US/Japan) buy them all within hours and the Russian move hardly caused a ripple to the US T Bill prices. IAW the US dollar basis central banks of the west and Japan will band together to counter Russian financial warfare moves. While Putin skirmishes with the west, China is taking copious notes on the strenghs and weakness of the combating parties.
IMHO all this fighting over the Ukraine has benefited China, not Russia, and Putin has to keep that in the back of his mind as he skirmishes with the US.
Its hard to conceive that the tiny country of Belgium would spend roughly 5% of its GDP buying US treasury bills in one month or that such a decision would be made so quickly.
Some entity in Belgium is doing a lot of buying of US debt, but on who's behalf is not really known.