Hundreds of works address the relation between President's authority as commander in chief and Congress's authority to declare war.
This review of two books provides an introduction to some of the issues: Gordon M. Goldstein, DRIFT The Unmooring of American Military Power By Rachel Maddow; WARTIME An Idea, Its history, Its Consequences By Mary L. Dudziak, Wash. Post, June 29, 2012.
Stephen P. Mulligan, Cong. Research Serv., R44761, Withdrawal from International Agreements: Legal Framework , the Paris Agreement, and the Iran Nuclear Agreement (Feb. 9, 2017)
Joel P. Trachtman, Terminating Trade Agreements: The Presidential Dormant Commerce Clause versus a Constitutional Gloss Half Empty, SSRN (August 9, 2017).