1
general::
Also, be on a tightrope. Take or be on a very precarious course, as in A university press must walk a tightrope to publish scholarly books and still make money, or The general was on a tightrope as to whether he should advance or retreat. This idiom transfers the balancing act performed by tightrope or high-wire acrobats to other concerns. [First half of 1900s]
American Heritage Idioms
2
general::
Phrase(s): walk a tightrope
Fig. to be in a situation where one must be very cautious. • I’ve been walking a tightrope all day. I need to relax. • Our business is about to fail. We’ve been walking a tightrope for three months.
McGrawhill's American Idioms And Phrasal Verbs