source: the people didn't have the power and/or enough resources to manage, control, and protect the land. # The land, if left to the Mentawai people, would be wasted.
target: the people didn't have the power and/or enough resources to manage, control, and protect the land. And since If the inhabitants of a land cannot protect and control it, the land will be wasted. The land, if left to the Mentawai people, would be wasted.