You may not have the causality quite right. An operational war the the US must fund almost always costs the services more than they get compensated by the DOD (20 to 30 % comes out of the services hide). The services have large fixed expenses. Thus, new procurements are slowed and non-obligated funds are swept back into the general pool to fund the actual conflict.
Given that the US will have to pick up a big share of the kitty fof this conflict, defense procurement may be ratcheted down for several years.