I tend to doubt the authors allegations. As a percentage of our GDP we ran higher deficits both during WW2 and the Reagan era.
That is true.
However, by percentage of GDP, we are spending less on Defense during the current GWOT than those times you cited.
Today spending, tends to be on other concerns.
Far more is going into straight entitlements, and not as much on building infrastructure and developing technology that actually pay-out in the long run.