In talking about defense budgets, it is important to address why nations spend so much money on defense. In addition to explicit goals such as ensuring national security and deterrence by investing in military capabilities to protect citizens and defend sovereignty, other reasons also exist. For instance, a strong military can enhance a country's geopolitical influence as the power of the military can be used to influence the actions and behaviors of other nations. Certain economic benefits can also be identified, such as the creation of jobs through both military positions and research and development. External benefits can be observed here as defense spending has the potential to drive technological advancements that may have other applications such as advances in communications, transportation, and medicine.
The issues with such high budgets are centered around opportunity cost and potential arms races. A continuing argument is that the billions of dollars spent on defense could have been spent on other areas such as education and healthcare that may be struggling with funding shortages. High defense budgets have also been known to spark arms races as nations try to "keep up" with each other's military advancements and capabilities.