Obama did not claim to obey international law, just Jeh Johnson did

Via Foreign Policy's link to CFR.org:

First: in the conflict against an unconventional enemy such as al Qaeda, we must consistently apply conventional legal principles. We must apply, and we have applied, the law of armed conflict, including applicable provisions of the Geneva Conventions and customary international law, core principles of distinction and proportionality, historic precedent, and traditional principles of statutory construction. Put another way, we must not make it up to suit the moment.

 Obama only uses words like "commitment" and "support."

Breaking the Geneva Convention on industrial targets that can cause secondary harm to civilians (passed in 1975), the US just bombed an oil rig in Al-Hasakah.