The phrase "pinch points" refers to places or situations where things can become difficult or tight, often causing problems or bottlenecks. Full definition
Look for pinch points and sharp corners, too. (thespruce.com)
In all relationships — whether within a family or a community or between nations — pinch points pose the greatest challenge. (dotearth.blogs.nytimes.com)
The directives stated American rights to free navigation through pinch points in the Northwest Passage over Canada [UPDATE: A wise Canadian comment contributor below notes a problem with the preceding language.] (dotearth.blogs.nytimes.com)