I debate austerity with one of its architects Lord Nick MacPherson
Ann, Keynes and I agree with you: When the economy tanks, government must spend enough to prop-up and stimulate the economy. This strategy works.
(But an even smarter approach would be to add the newer, more accurate and effective insights of Modern Monetary Theory. Spending by the government is investing; the national debt is just a record of government money that's been invested. It's not, or shouldn't be, frightening or even worrisome; but people insist on equating the dynamics and restraints of their personal budget with the government's, which has the great advantages of using fiscal and monetary policies, and the power to print a fiat currency. Which no other entity has. But going with neo-Keynesianism is better than going with Milton Friedman's austerity balderdash.)