The United States has previously had a critically important stance that it would not use nuclear weapons or other weapons of mass destruction unless nuclear weapons were used against us. While this stance is important to our policy of M.A.D. in the current geopolitical landscape, a prudent next step for Congress would be to take this a step further, and require that any preemptive nuclear strike, or other weapon which has strategic significance, such as large-scale cyber warfare, or mass destruction capabilities, require Congressional approval before they can be deployed.
Likewise, this should not interfere with the Executive Branch's ability to retaliate WMD usage against the United States. This ensures our commitment to preserve life worldwide at all costs, unless otherwise threatened.