There is, in the extensive literature on negations, much discussion of the concept of "issue linkage." In fact, it gets tossed around a lot without ever getting an explicit definition. But it’s a very helpful concept that arises out of the literature on international relations. And it has its roots in a 1979 article in International Organization by Robert D. Tollison and Thomas D. Willett, An economic theory of mutually advantageous issue linkages in international negotiations. As they wrote:

[B]y linking the two negotiations so that high benefitsgo to A in one area and high benefits go to B in the other, there may be a possibility to secure agreement in both negotiations in a way that brings benefits to both countries and brings the outcome much closer to the aggregate efficiency or potential welfare frontier.

(The "aggregate efficiency frontier" is the authors’ term for the best outcome for the most people.) If this sounds a lot like basic horse-trading, well, that’s probably because that’s what it is. But, as the authors pointed out even back then, making the trading that naked "is extremely unlikely to be politically feasible." For whatever reason (we human beings don’t like feeling like commodities, various bribery statutes may forbid certain kinds of trades), we don’t like to make our horse-trading that naked.

So how should lawyers engage in issue linkage? There are a few ways that have worked well over the years of asking for some degree of quid pro quo without having to sound like Hannibal Lector toying with Clarice Starling. For example;

• Professional courtesy. Stripped of its cultural baggage (and make no mistake, professional courtesy is a cultural phenomenon), is a way of allowing horse-trading on small issues without making an explicit quid-pro-quo. By recasting the issue as one of "professional courtesy," one can imply to the other side that small concessions will be respected without compromising larger issue. (This works only if it’s not abused.)
• Argue explicitly for linkage. Remember when I pointed out that lawyers don’t argue well in negotiation because arguments often don’t matter? Well, sometimes maybe they do. But it’s not in convincing the other side of the overall merits of our case. It’s in convincing them that the issues we seek to trade off against each other actually are connected in some way that justifies the trade.
• Explicitly unlink some issues. When you explicitly unlink an issue (like attorneys’ fees) from other issues, you are actually doing two things. First, you are explicitly saying that you have unlinked one issue from the others, meaning that no other negotiations will affect it, at least formally. But secondly, you’re sending an implicit signal that all others issues are considered fair game to trade off against each other.