protection against something
bulwark - defence
A ‘bulwark’ in a literal sense is a solid wall-like structure built for protection or defence. It is more commonly used in a figurative sense to refer to something that offers strong fortification or support against something dangerous or unpleasant. Often encountered in relation to politics or legal matters.
The newly passed legislation provides citizens with a necessary bulwark against online data theft.
This country’s ingrained democratic principles stand as a bulwark against the potential rise of an authoritarian or totalitarian regime.
We established our base on high ground as the terrain provided a natural bulwark against enemy attacks.