on a razor's edge
US /ɒn ə ˈreɪzərz ɛdʒ/
UK /ɒn ə ˈreɪzərz ɛdʒ/

1.
危機一髪の状況で, 瀬戸際で
in a very dangerous or precarious situation; at a point where a small change could have either a very good or very bad result
:
•
The company's finances are on a razor's edge after the recent losses.
最近の損失の後、会社の財政は危機一髪の状況にある。
•
The negotiations were on a razor's edge, with either side ready to walk away.
交渉は危機一髪の状況で、どちらの側も立ち去る準備ができていた。