旷日持久

Origin and story

In the Zhao section of the Zhanguo ce, Zhao She objects to his state's costly recruitment of Tian Dan from Qi to command against Yan. He argues that a commander concerned with Qi's advantage may prefer to wear down both Zhao and Yan rather than win decisively for Zhao. His warning describes years of campaigning exhausting men, equipment, and public stores.

The phrase appears within that argument about the danger of a prolonged war. It expresses duration combined with wasted or heavily consumed time. Modern use extends naturally to negotiations, disputes, and projects that drag on; it is not normally praise for admirable persistence.