at the cutting edge of something —(also: on the cutting edge of something ) involved in the most advanced developments in a particular field:
- It is unrealistic to expect to be at the cutting edge of the fashion industry for anything longer than fifteen years.
on the knife-edge of something —(also: on the razor’s edge of something ) on the brink of smth. bad or dangerous:
- The expansion of trade hasn’t closed the gap between those who live on the cutting edge of the global economy and the billions who live on the knife-edge of survival.