The Washington strategists calculated that if a war breaks out, Russia would hold leverage due to the gas pipelines that offer cheap energy to much of Europe. With the countries in western Europe, mainly Germany, being addicted to cheap Russian gas, they would probably not be forthcoming in supporting the American plan to arm Ukraine to teeth, the White House calculated.
It then became imperative for the US to thwart the key pipeline and forestall the 'weaponization of gas' by Russia.