In the crowds of Washington's Union Station last week, I bumped into George Mitchell. We were both in the city for Barack Obama's inauguration, but at that point there was only speculation that George might be made US special envoy for the Middle East – it wasn't until I returned to Ireland that the appointment was confirmed.

President Obama in his inaugural address signalled a new direction for US foreign policy. The posting of George Mitchell and the referencing of his very significant role in the Irish peace process hint at a more focused engagement by the US in seeking to secure a peace settlement between Israel and the Palestinian people.

But as George and I both know from our separate but related experience in Northern Ireland, making peace is a difficult, exhausting and, at times, hugely frustrating process.

George Mitchell had been a very successful and influential Senate majority leader for the Democrats. He was known as someone who could broker a deal between opposing groups.

In January 1995, he became President Clinton's secretary of state on economic initiatives in Ireland and, later that year, he was appointed to chair the International Body on Arms Decommissioning. The report produced by this group in January 1996 contained six broad principles of democracy and non-violence, which became known as the Mitchell Principles.

But it is as the chair of the all-party negotiations that led to the Good Friday Agreement that George is best known in Ireland and elsewhere. Initially, the Unionists and the British government opposed his appointment. Neither wanted an independent person holding down such a key position.

When eventually George Mitchell made it to Castle Buildings in Belfast where the negotiations were to take place, the Unionists kept him waiting in a side room for two days while they debated whether he should be allowed into the room. And thereafter, they embarked on a constant campaign of challenging the ground rules and structure of the talks as a way of undermining him.

There was more to come. In late 1996, several London and Dublin newspapers carried headline stories alleging that Martha Pope, George Mitchell's chief aide, was having an affair with one of our senior negotiators, Gerry Kelly. The story was rubbish, but it had been deliberately planted by anonymous "security sources" to damage George Mitchell.

So, between interminable negotiations, almost weekly crises, dirty-tricks efforts from British securocrats and endless filibustering by the Unionists; not to mention the mindnumbing detail of a peace agreement, George Mitchell had his work cut out.

He patiently plotted a course through all of this. He brought to the process a legislative and judicial experience that saw the negotiations format changed from one of large cumbersome meetings to one of smaller groups of negotiators, usually involving the leader and deputy leader of the parties. This provided for a greater focus on the detail of the issues, and it facilitated a more workable and productive arrangement.

It also suited his particular style of getting things done. George spent a great deal of his time in side meetings with the parties. Throughout these, I found him to be goodnatured, humorous and tolerant. It is this experience that will stand him to good stead as he embarks on his journey to the Middle East.

Of course, a lot will depend on the terms of reference he has been given. Ultimately, however, no matter how good he might be, George Mitchell will not produce a negotiated agreement in the Middle East. That is for the Israeli government and the Palestinians. But to have any hope of achieving that goal, the US and the international community have to engage with this issue in a concentrated way and treat the participants on the basis of equality.

In the Irish peace process, the US involvement was generally seen as a good thing. That may not be so in the Middle East. That could be a complicating factor facing George Mitchell.

Moreover, if any renewed effort in the Middle East to reach an agreement is reduced by either side to a tactical game of winners and losers, in which the object is to use the negotiation process to inflict defeats, then it will not work. It will simply be a repeat of past mistakes and lost opportunities.

In a peace process, the goal must be an inclusive agreement that is acceptable to all sides, is doable, deliverable and sustainable. That means enemies and opponents creating space for each other. It means engaging in real conversations and seeking real solutions. It means accepting that dialogue is crucial and that means recognising the right of the Palestinian people to choose their own leaders, their own representatives.

The Israeli government and other governments have to talk to Hamas.

The recent assault on Gaza is a brutal reminder of the destructive power of war and of the human cost of failure. It is time all of this was brought to an end.

But breaking the cycle of conflict will mean political leaders – Israeli and Palestinian – taking real risks for peace. They will need help and a real and unrelenting international effort to construct a durable peace settlement that provides for two states, but in particular, for a Palestinian state that is sustainable and viable.