A perilous policy, procedure, etc: Nixon remained skeptical of Kissinger's high-wire act in Vietnam
[1970s+; fr high wire, an 1880s term for the funambulist's high tightrope]
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with high-wire act
A risky job or operation, as in The university press is not allowed to either make or lose money—that's a high-wire act. This expression alludes to the aerialist performing on a tightrope stretched high above the ground.
[ ; mid-1900s