Từ điển Hán Nôm

(1) lit. military tactics on paper (idiom)
(2) fig. theoretical discussion that is worse than useless in practice
(3) armchair strategist
(4) idle theorizing
(5) cf Zhao Kuo 趙括|赵括 leading an army of 400,000 to total annihilation at battle of Changping 長平之戰|长平之战 in 260 BC