Even if the final goal was something different, economical sanctions always aim where it hurts, where there is money, and a lot of people around Putin have money.
If they had something else in mind, they would still do the same => diplomatically and economically isolating your enemy. It cost almost nothing and it can hurt as much as wars if done right.
One day there should be laws about economical wars, because today in this globalized world, you are forced to be in the global market, and to use the global market as a tool of war shouldnt be a unilateral decision without trials based solely on ideological and geopolitical stances, since people are in the balance too.
US fears Russia because it offers an alternative that China is not. For exemple : Snowden and world spying. Russia can counter US spies and can spy themselves ( Nuland phone chat). They can provides advanced weapons to countries like Syria or Iran. They offer an alternative internet without censorship (RuTube etc.), they can supply gas and oil to countries like China or India, they can launch military satellites. They try to avoid dollars paiements in international exchanges etc.
A strong Russia is a threat to the US world hegemony.
And they are already at economical war. When Visa and Mastercard initiated an embargo on Russia, Putin decided to create a new credit card system.
You can also remember when EU took the russian cash in Cyprian banks...
And, finally, Russia can now propose some "counter-propaganda" medias, as never seen before , since at least, 20 years.