"Congressional Authorization: A Fading Tradition in US Wars. A recent analysis has highlighted a concerning trend in the way the US government approaches war authorization. While former Presidents George H.W. Bush, George W. Bush, and Ronald Reagan all secured explicit approval from Congress before launching major military conflicts, their successors, Barack Obama and Bill Clinton, have largely sidestepped this requirement. This shift raises questions about the balance of power between the executive and legislative branches, and whether the checks and balances that are fundamental to American democracy are being eroded."
Both Bushes and Reagan won authorisation for wars, but Obama and Clinton ducked the requirement.
