The enemy may return in force; we must be prepared.
Tips
history
Literally 'to return in a swirl of dust.' From a Tang dynasty poem by Du Mu (杜牧) about the fall of Xiang Yu (项羽), who could have made a comeback after defeat but chose suicide instead. The idiom now means rallying after a setback.
usage
Can be positive (making a comeback in business/sports) or negative (a problem resurfacing, an enemy returning). Context determines the connotation.