Military expenditures can be deceiving. In the case of Saudi Arabia, they have purchased tons (literally) of military equipment from the United States which is shrink wrapped and sitting in air-conditioned warehouses. Why? One, because they can afford it, two it represents strategically pre-posiitioned equipment for the United States. Also regarding the Saudi armed forces, much of it is manned by Pakistani volunteers. The Saudis are very wealthy and wealthy people do not don uniforms and fight. The Saudi military is very capable but it is not as powerful as their checkbook makes it look.
USMC 2013-2017 (Combat Logistics)