In his June 25 op-ed, “Congress has a job to do on Iraq,” Sen. Tim Kaine (D-Va.) insisted that the president must seek authorization from Congress before using military force in Iraq. Congress has the constitutional responsibility to authorize force to prohibit an unchecked, all-powerful executive from unilaterally committing U.S. forces.

However, for Congress to ensure that the president seeks that approval, it must take away the never-ending authorization it gave with the 2001 Authorization for Use of Military Force and the 2002 Iraq authorization. Both are far too broad and do not include sunset provisions. Until they are repealed by Congress, they remain available to the president.

Mr. Kaine was right to argue that the president should not rely on these resolutions to justify force in Iraq. But removing those authorizations would force the president to argue his case and force Congress to fulfill its responsibility to cautiously deliberate on the consequences of war. Perhaps then the United States would not rush to military solutions.

Elizabeth R. Beavers, Washington

The writer is legislative associate for the Friends Committee on National Legislation.

Sen. Tim Kaine (D-Va.) argued persuasively that, under the Constitution, the president needs to come to Congress before using military force in Iraq.

No court is going to resolve this issue. Courts have steered shy of defending congressional war powers when Congress has failed to act, essentially saying: If you want to protect your war powers, you have to speak up. If you run away like the Iraqi army, you’re on your own.

That’s why it’s crucial that members of Congress speak up now, as Mr. Kaine and Sen. Rand Paul (R-Ky.) have done. Effective enforcement of the Constitution on war powers is political. In August, more than 100 members of the House told the president he needed to come to Congress for authorization before bombing Syria; he did so, conceding not that he was legally bound to do so but only that it was the right thing to do. That’s all we need now.

Robert Naiman, Washington

The writer is policy director for Just Foreign Policy.