Who has the authority to declare the Iraq war is over?

To declare War, grant Letters of Marque and Reprisal, and make Rules concerning Captures on Land and Water;

Article I, Section 8, of the Constitution of the United States

As everyone knows, Congress has the authority to declare war. But, who has the authority to declare the end of a war? Once war is declared, does the "Commander in Chief" have complete control over the tactics and length of a war?

This section of the Constitution continues with;

To raise and support Armies, but no Appropriation of Money to that Use shall be for a longer Term than two Years;

To provide and maintain a Navy;

To make Rules for the Government and Regulation of the land and naval Forces;

To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;

To provide for organizing, arming, and disciplining the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress;

Congress has a great deal of authority over the military. The only reference to military authority of the president is;

The President shall be Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States

Article II, Section 2, of the Constitution of the United States

The idea of an open-ended war with a continuously redefined goal against an ambiguous enemy is not directly addressed in the Constitution. Some ideas are so stupid that you can't fault the writers for not anticipating the possibility. All the same, here we are. How do we put an end to it?

Since Congress has the authority to declare war, I would say that they have the authority to declare that a war has ended. Setting a time for our soldiers to leave Iraq is not micromanaging the war. It is fulfilling their constitutional duty.