Comment by lumost

To my knowledge, this has only ever been done successfully during ww2. The mechanism used was semi-forced lending via war bonds. The war bonds were predominantly purchased by wealthy individuals and the rate of return was lower than all alternatives.

The spending of war debt on the other hand went out to common individuals. As the war debt was never repaid, encumbants would spend the next 2 decades with lower rates of return compared to new market participants.