What would happen to the moon if inertia disappeared?

Inertia keeps the earth and moon system as it is until an external force acts on it (say a collision)

so there would two scenarios:

#1: Where there would be something else replacing inertia, which would decide of what would happen in the above said situation ... and it will lead to a different set of laws of motion

#2: there won't be a replacement, no laws, which wrecking havoc in the universe ... and probably throw in the possibility of a existence of life into question

Inertia would make the moon travel in a tangential line to its orbit, had gravity suddenly disappeared.