From Breadwinners to Bystanders: the Death Spiral of the American Working Man

Because birthrates do not really depend on those men since they can't marry anyway, nor is the economy, they are pretty much expendable and Soviet style loss rate will be acceptable. With that tolerance to losses, America can achieve massive victories.

Quality of the future generation will also improve since women will all have kids - alone - from a small pool of high quality men (those who can get laid on Tinder).

Once the military men retire from service, they can be given property and positions of power in the new lands they take, to create a core of newly forming elites, which will be fair given their sacrifice and will give them equitable, deserved station in life.