I believe we should monitor our ally’s use of defense spending in areas the US military is tied up for multiple reasons. The first being, we must not be the only country helping to solve world issues. The second, the US military budget is grossly inflated, mainly for having to take on the task of solving world issues or reducing the influence of non-state actors with virtually little help from our allies. Thirdly, as a country with a strong military, we must analyze the capabilities of our allies in the case of future war and how they spend their money in order to understand how effective of an ally they will be in the future war.
There is no harm in analyzing other ally capabilities and defense spending. This can be a political tool to help encourage other states to take on a roll so the United States can use its vastly large defense spending on other real Federal programs, or reducing our debt.