kyokyo jitsu jitsu
A long time ago, I posted the origin/metaphorical basis for the yoji 海千山千 and asked you to guess the import. This time, I'll tell you the definition of this one, and let's see what you can come up with in terms of why it means what it does.
Definition:
互いに策略を尽くし、相手の隙をねらって必死で戦うこと。
Translations:
1. An extremely well-matched contest between two skillful opponents.
2. A mutually exhausting combat, full of clever deceptions and well calculated attacks.
3. Probing a hostile party for weaknesses.
And let's back up a bit and take a look at the definition in direct translation because it's SO hard core, and full of good stuff:
Having mutually exhausted all of your best-conceived strategies, engaging in a desperate battle to find the chink in your opponent's armor that will let you bring them down first.
- 互 of 互い (たがい;tagai) happens to be my favorite kanji, mostly because I like the way it looks, but it's meaning, 'reciprocity,' is pretty cool too.
- 策略を尽くす (さくりゃくをつくす;sakuryaku wo tsukusu) means "to exhaust all of your ideas or strategies" and can be used any time you don't know how to deal with a recurring problem.
- 隙 (すき; suki) is the chance presented by a weak spot in someone's defenses; a chink in someone's armor.
- 必死 (ひっし; hisshi) is a な type adjective used to indicate frantic desperation, but it's connotation of "inevitable death" makes it a lot more dangerous.
これは虚虚実実の駆け引きだ。
This is some EPIC haggling, right here.
弱体化した米国はイランに対して鞭とニンジンを使い分け虚虚実実の神経戦を演じている。
The weakened rice country (America) has been acting the part of the disciplinarian, doling out punishments and rewards as it sees fit, in it's enduring, nerve-wracking battle of wills with Iran.
Other usages I've found include descriptions of resilient types of weeds, and particularly competetive chess matches.

例文:
彼と8時間以上、虚虚実実のチェスの戦いをしたあげく、彼の弱点をやっと見つけた:チェスボードでぶっ殺されることです。
After eight brutal hours of strategic chess scheming with no success in sight, I finally found his one weakness: being beaten to death with the chess board.
So tell me, what do you think gives these two repeated characters (Hollow Hollow Truth Truth) the meaning that they carry today?