When I lived in Edinburgh (in Old Town, though very close to New Town), I enjoyed the occasional stroll across beautiful Princes Street Gardens to buy some Thornton's toffee or ice cream. Suppose the head honchos of Old Town, my part of Edinburgh, went to neighbouring West End one fine morning to beat up some random stranger or maybe to commit theft. As a result, the yobs-in-chief of New Town decide that I may no longer cross Princes Street Gardens for delicious Thornton's treats.
More generally, suppose A does something of putative moral blameworthiness, and that B, who is not immediately affected by the reprehensible act and has not had a hand in its doing, is under A's jurisdiction. B is doing business with C. Now because of A's morally reprehensible act, D tells B, that B is no longer allowed to do business with C. If D nonetheless catches C doing business with B, D can punish C very severely.
This is about what the sanctions enacted on certain Russian firms by the EU and the US do. If these actions sound crazy and unfair (to me and Thornton's and to B and C, respectively), it is because they are. Of course, it will be argued that they are enacted in order to influence important people in Russia to support peace (even though it does not take two to get peace; one will suffice). What the sanctions also accomplish is to reduce the opportunity cost of war. Less trade, less to lose. Certainly, less exchange also means less cross-cultural understanding. The immediate goal of the sanctions may also fail to be realized, since Russians may not direct their displeasure at the Kremlin, but instead lower their opinion of the West (according to the thought experiment above, this would be without justification unless restricted to Western leaders only).
When the effects of an action are theoretically uncertain, some consequentialists are brash and choose to believe that some felicitous mechanisms will dominate, which - since the ends justify the means - indicates to them that unsavoury actions must be countenanced (many revolutionaries belong to this crowd). Other consequentialists recognize the fact that we are too ignorant to tell whether happy results will follow, and conclude that unsavoury actions are clearly to be avoided.
Alas, the brash folks in Washington and Brussels have now besmirched their moral record as far as deontology goes. The individual may only hope that Providence sees to it that the good consequences outweigh the bad ones.