Copyright Is the Sole Enforcement Mechanism for Open Source

Every open source license is a conditional grant of copyright, and copyright is the only enforcement mechanism that sustains open source. MIT, Apache 2.0, GPL, AGPL: the author holds copyright, the license grants permissions under conditions. Violate the conditions and the grant terminates. This is not unique to copyleft. Permissive licenses depend on the same foundation. Remove copyright and there is no right to grant, no condition to enforce, no chain of derived works to sustain. The entire structure collapses.