On February 4, a US fighter jet shot down a surveillance ballon from China. China has insisted that it was a weather balloon that had drifted off its designated course. According to a US senior defense official, the balloon was trying to gather information about US military sites. The Chinese government denounced the move as an obvious overreaction. However, it’s not unusual for governments to use surveillance balloons to spy on other countries because they can take clearer images. As a matter of fact, the use of surveillance balloons can be traced as far back as the 1800s. They became an important tool for the military in World War I and II.