It would be truer to say the agreement was between several world powers and Obama, as the Senate didn't ratify.

did the senate ratify starting a war with iran or president is ok to bomb with isreal at will but any agreement requires “ratification” by senate?!

Re starting wars, you’re preaching to the choir.

Re international agreements: yes, the idea is that _broad support_ is required for binding international agreements. Senate ratification represents broad support.

The JCPOA was written in pencil.