What they're talking about is the creation of the Military Industrial Complex but without directly saying it. New Deal programs were replaced with military ones and American production shifted heavily into a constant state of arms production.

The reason it "helped the economy" had nothing to do with war or violence, just the fact that military production lines require massive amounts of labor and are centrally planned and funded by the state.

If America had decided to centrally plan light industrial production and invest in infrastructure (continuing New Deal policies) it would have had the same effect, but you can't genocide Koreans with trains in Chicago.

The new deal was cool and good and helped alleviate a lot of suffering during the depression

its false conservative cope and just a page away from their real ideological sticking point of 'the new deal prolonged the great depression & hoover would've solved it by doing nothing'

Idk how much effect the New Deal had, but being more or less the only industrialized economy that wasn't bombed flat with incredible loss of human life worked out really well for the US.