What is a War Bond?
A war bond is a bond issued to finance war.
How Does a War Bond Work?
Let's say that Country X attacks Country Y. Country Y has a smaller military and defense systems, but wants to defend itself. It decides to enlarge its military, beef up its satellite and intelligence systems, and buy planes and weapons. These things cost billions of dollars that Country Y does not have in its treasury at the moment, so it borrows the money from its citizens (and foreign investors) by issuing war bonds. The government uses the proceeds to fund its defense initiatives, and because of its larger, faster, more capable military efforts, it is able to defeat Country X.
Country Y repays the war bonds with revenue from its taxpayers.
Why Does a War Bond Matter?
The United States issued war bonds during World War II as a way to raise money for the war effort. They were zero-coupon bonds, which means they were sold at a discount to face value and did not pay interest. They were repaid at maturity. Many people bought the bonds (that is, lent the government money) to show their patriotism.