noun
military expedition deep into enemy territory
A yojijukugo describing a long-distance military campaign far from home, often implying a risky, isolated advance.
懸軍万里の遠征は、補給線が伸びきって危険だ。
A military expedition deep into enemy territory is dangerous because supply lines become overextended.
A yojijukugo composed of 懸 (to hang, suspend, risk), 軍 (army), 万 (ten thousand, myriad), and 里 (ri, an old unit of distance). The phrase evokes the image of an army venturing far from its base, suspended in distant lands.