firebreak

An area cleared of all flammable material to prevent a fire from spreading across it.

The firefighters used a bulldozer to clear a firebreak in the forest to try to contain the forest fire.

When a fire does break out, it tends to burn longer and further because the natural firebreaks that might have existed from previous, smaller fires are not there.

Any separating barrier.

That policy could consist of a statement that the declaring nation would not be the first to use nuclear weapons. This would strengthen the firebreak between the use of conventional and nuclear weapons.

First, it serves to demonstrate that the practice of sustainable critique […] need not be impossibly philosophically rarefied […] Second, it serves as a firebreak against the unrelieved negativity that, it is sometimes charged, follows from Adorno's practices of reflexivity.