Final answer:
Congress exercises a check on executive power through its 'power of the purse,' requiring presidential expenditures, including those on wars, to be approved via an appropriations bill. This system of checks and balances is designed to maintain equitable power distribution between Congress and the executive branch, particularly regarding military funding and expenditures.
Step-by-step explanation:
The control of government spending by Congress, also referred to as the "power of the purse," acts as a significant check on the executive branch's power, particularly in terms of war expenditures. Section 9 Clause 7 grants Congress the sole ability to control government spending, which means that the president cannot spend public money without Congress's approval through an appropriations bill. This ensures a balance of power and prevents the president from having unilateral financial authority.
Furthermore, Section 8 Clause 12 of the Constitution explicitly states that Congress has the power to raise and support armies, inferring that while the president is the Commander in Chief and can engage the military, Congress must approve funding for such actions. This ability is one of Congress's most substantial tools to ensure compliance with their policy-making priorities.
In practice, the dynamic between the executive and legislative branches involves ongoing negotiations wherein the president proposes a federal budget, and Congress then scrutinizes, amends, and approves this budget. Over time, though, the increase in the use of executive orders and other mechanisms has expanded presidential power, particularly in foreign policy and military engagements, reflecting an ongoing struggle for power between the branches.