Self Education - War Powers Resolution of 1973

In an effort to clarify the rolls of the executive and legislative branches of government in the use of military force, Congress passed the War Powers Resolution of 1973 over the veto of President Nixon. The resolution was instituted in an effort to provide a check and balance between the two branches. It lays out rules by which the President, as commander-in-chief, may involve United States troops in military conflicts without a declaration of war and is supposed to hold the President in check from entering wars/conflicts that the people of the United State do not support. The War Powers Resolution was born out of the Vietnam Conflict. There have been many questions as to the constitutionality of the law and many presidents have pretty much ignored it. It has been reported that President Obama has said that it does not apply to the Libyan conflict. Why do we have such and Act that is not enforced? And if it does not apply, where is the check and balance for the executive branch of our government.