The latest happenings with JMM political party in Jharkand has many of the same traits as that of what JD(S) done a few months back to BJP( yet again!) in Karnataka. Say yes, say no, say maybe and keep the other party frustrated and guessing. These political outfits played good cop - bad cop with the other party and no one knows who is to be believed and who is the decision maker. Trying to straddle (eat & keep the cake too) is the main motivation for these kingmakers. Who says you should be a major party to get handsome gains? In these days, the smaller ones make far more coalition governments with enough monisterial positions and horse-trading behind them. Ethics is something these parties dont know and cant expect them to share anything according to any unwritten rule (Even wriiten constutional rules and laws and openly flawed by politicians).
Coming back to the strategy, I have realised that this is one of the best strategies to use against someone to see what the other party will consider doing and to what extent under each of the conditiion. Call it testing the enemy's response to each of the scenarios and signals you give by playing both sides. From a personal experience I can tell you that this gets worse if the other party talks to you in a friendly manner and is emotionally blackmailing you by signalling consequences.