Over the years, the contention that the Israeli-Palestinian conflict be solved only through “direct talks” has become almost a mantra, especially from the Israeli government and its allies.

But direct talks between implacable foes, without active mediation, may be the worst possible way to try to settle the conflict. Facing one’s adversary directly across the table heightens psychological barriers even to a mutually beneficial deal.

So if the Israelis and Palestinians embark on yet another effort to end their conflict, active and vigorous U.S. mediation can play a crucial role to address the psychological and relational barriers that to date have frustrated talks.

Research at Stanford on the barriers to conflict resolution shows that psychological processes play a key role in guiding the perceptions and behavior of those trying to end particularly intractable or violent political conflicts.

The parties to the conflict are prisoners to beliefs based on their history, which color the way they see both themselves and their adversaries. As a result, it is hard for them to interpret information, evaluate risk and set priorities in a purely rational way. Even when an advantageous deal is on the table, they are psychologically disposed to reject it.

These biases come to the fore especially when the parties face each another directly across a negotiating table. Experimental research shows that each side comes to the negotiations believing that they see the world as it really is, while the other side has an unreasonable or mistaken view.

This is classically illustrated in the case of Israelis and Palestinians. Israelis see themselves as facing an existential threat from those with whom they are expected to negotiate. Palestinians see themselves as victims of an illegal and unjust occupation.

In the Palestinian view, one shouldn’t have to negotiate a peace with the burglar who has stolen your possessions. In the Israeli view, one shouldn’t be expected to negotiate a property boundary with a neighbor committed to destroying you. It is implausible to expect the parties to engage in bargaining involving an exchange of interests when they start from such fundamentally different points of view.

Another psychological phenomenon that comes into play is known as “reactive devaluation” — a tendency to minimize the value of any concessions offered by the other side: “If they’re prepared to offer us this, it can’t be worth much.” However if the concession is offered through a third party, it may be evaluated more realistically.

A third psychological phenomenon that makes direct talks without a strong mediating role more difficult is a natural human propensity to attach greater weight to prospective losses than to prospective benefits of equal magnitude. We focus on what we’re sacrificing rather than what we stand to gain.

A fourth is the tendency of both sides in a conflict to enter negotiations seeking what they see as justice, or a redress of their grievances. This is a natural desire, and no agreement is possible if it does not meet minimum standards of justice. Nevertheless, the quest for justice may ultimately stand in the way of achieving a settlement because the two parties have such divergent views on the past suffering they’ve experienced, and on who is responsible for it.

Mediation can help mitigate all these phenomena — which is where the United States, as the only actor that has the trust of both sides, comes in.

But formal mediation is no magic bullet. Ultimately, our research suggests that peace is possible only when each party is prepared to articulate a vision of a future that meets not only its own demands, but that the other side would also find bearable.

Building peace requires the parties to begin establishing patterns of behavior that enable them to believe that mutual trust is possible. The parties must acknowledge the losses an agreement will impose on both sides to enable them to secure the benefits of peace.

Getting the United States engaged as an active mediator guided by these principles is only a first step, but a critical one. There is no assurance that a revived peace process will succeed even with active U.S. mediation. But without it, such a peace process is almost certainly doomed to failure.