Meanings

loss by default

playoff match to determine promotion and relegation (played between bottom-ranked teams of the higher division and top-ranked teams of the lower division)

do-or-die resistance

fighting with all one's might

pincer operation (tactic)

the Spring and Autumn period and the Warring States period (Chinese history)

return to the line (of battle)

daimyo in the Warring States period

mopping-up operation

loss of fighting spirit

turbulent (troubled) times

slowdown strategy

putting up a good fight against some odds

opponent

competitive lobbying

exposure tactics

(engaging in a round of) mutual criticism

obstructive tactics

wildcat tactics

operations (a strategy) on two fronts