trip wire

"Getting to YES" の "What If They Are More Poweful?" の章から引用します。
Formulate a trip wire. Although your BATNA is the true measure by which you should judge any proposed agreement, you may want another test as well. To give you early warning that the content of a possible agreement is beginning to run the risk of being too unattractive, it is useful to identify one far from perfect agreement that is better than your BATNA. Before accepting any agreement worse than this trip-wire package, you should take a break and reexamine the situation. Like a bottom line, a trip wire can limit the authority of an agent. "Don't sell for less than $258,000, the price I paid plus interest, until you've talked to me."
(Note: BATNA short for Best Alternative To a Negotiated Agreement)
この本の著者も "trip wire" を "trip-wire" とも書いたり一貫性がありません。多くの辞書は "trip wire" ではなく、一語の "tripwire" としています。
・Oxford English Dictionary: A wire stretched close to the ground, working a trap, explosion, or alarm when disturbed and serving to detect or prevent people or animals entering an area.: There were no guards, no alarms, no more tripwires after those we had evaded.
・Dictionary.com: a wire that activates a trap, camera, or other device when stepped on, tripped on, or otherwise disturbed.: The emotions of Democrats are on a tripwire, ready to react at the slightest provocation.