Spend say 10% of the war money on development of alternatives to oil. Then cut off the money supply to Saudi Arabia et al, confiscating financial assets in the West, and cordon off the region. There would still be some force required to enforce the blockade but that’s all.
Staking everything on the ‘oil alternative’ shifts solving the problem into the future by an unspecified amount. This time machine of ours is going to be busy.