War bonds are issued by a government to help finance military activities in times of war. These bonds do not pay interest and have a below-market-rate of return. US Government war bonds were issued at 50-75% of face value with a 10-year maturity. Because of low returns, governments must appeal to its citizens to invest in war bonds.
In 1917, the US Government issued Defense Bonds, also called Liberty Bonds, which were the predecessor to war bonds. These bonds were used to help finance US military activities during World War I. The US Government raised $21.5 billion worth of Liberty bonds. The government was able to raise $180 billion worth of war bonds during World War II.