Really naive to think so.......
On top of my head, the first thing US can do, and most probably WILL DO in the near future is increase oil production and drive down the price, US wasn't really depending on Oil and Gas sector to survive, with price cap, and if US expand shale oil/gas extraction by 2 Millon barrel a day to 4 million barrel a day, it will drive oil price down to below $60, which mean Russia will be losing money by selling oil to China and India on discount. That's number 1.
Another thing US can do is to go after ALL essential machine and tooling, US provide a lot of advance machine tooling to Russia even after sanction because it deems essential for Russian Population (Same reason why Samsung or Apple has not left Russia), if that stop, in 3 to 6 months, it will take down Russian advance production capability, and they can't buy them from China, because US sell them to China. Things like integrated IC circuit and High Density Aluminium product.
Things EU can do is first of all, CUT RUSSIA COMPLETELY off SWIFT. This still has not done. Second, EU can dip into their vast undersea shale, which would also drive oil and gas price down. And finally, EU
If you find a post triggering then report it instead of responding in kind or worse. You could be penalized for this post but I have showed leniency for now.
But USA is NOT trying to colonize Syria and other countries.
A war can be fought for fulfillment of LIMITED political objectives in a particular region:
Americans wanted to dismantle Al-Qaeda Network in Afghanistan (Operation Enduring Freedom) = objective accomplished.
Americans wanted to bring an end to Saddam regime in Iraq (Operation Iraqi Freedom) = objective accomplished.
Americans wanted to bring an end to Qaddafi regime in Libya (Operation Odyssey Dawn) = objective accomplished.
Americans wanted to bring an end to ISIS