I see no reason to believe that the draft prevents wars.
I sorta see the authors point, but it’s like extinguishing a fire by instead of dousing it with water throwing fire on it and letting it burn out on its own. Which is stupid. But some people can’t get over the tact that the modern mass army is attractive to the poor, and they want the richer to suffer for it.
There is something to this, in that in the old days war was for princes to run and the nobility and mercenaries to fight. Unsurprisingly they were of relatively limited scope, shorter duration, and les cost. But that was before democracy, industrialism, mass ideology, propaganda, etc. You can’t go hack by throwing richies in the mix. That world is gone.
More to the point is money. We can’t fight endless wars if we’re bankrupt, or not as many and not forever. And don’t worry, we are bankrupt; most of us just don’t know it yet.