Cuba Libre: Is Cash Laundered by another player earmarked for a particular LimOp?
It's not explicit in the rules, but the way Operations are payed for is that the Faction chooses an Operation, pays the cost in resources and the follows the Operation procedure. So the Faction has the right to do an Op by the sequence of play order and the paying of the Op is done during the Operation, after the Operation type has been declared.

On the other hand, to Launder a Limited Op, the Faction needs to Launder the cash to be granted the free Lim Op. If there is no Launder there is no free Op. So it seems that if another Faction wants to Launder cash they should first spend the stash and then the active Faction could get a free Op... which could be anything (except Construct 3.3.5).

Also, the rules for Negotiation 1.5.1 are clear in that there are no binding agreements in this game, so there is that.