A Handshake in Belfast - NYTimes.com When Queen Elizabeth II, Britain's head of state, shook the hand of Martin McGuinness, the former commander of the Irish Republican Army, on Wednesday, it was so simple a gesture. Yet, in the context of the Northern Ireland peace process, it was necessary, even courageous. It has been 14 years since the I.R.A. ended its war against British rule and signed the Good Friday peace agreement. In that time, the Catholic nationalists have become an integral part of the political process. Mr. McGuinness is the province's deputy first minister and works closely with Peter Robinson, the Protestant unionist who is first minister. They say they are committed to the peace plan, which has become a model for ending other armed conflicts. But there is still much to do. There are big problems of economic disparity and segregation between the Catholics and Protestants. Extremist splinter groups continue to attack British targets. After so many years of bloodshed - the "Troubles" lasted three decades and killed more than 3,600 people - some Catholic dissidents and I.R.A. victims are still bitter and opposed the handshake. But Mr. McGuinness and the queen should be applauded for their contribution to reconciliation. They are powerful symbols themselves. Mr. McGuinness admits he was on the front lines in the war with British forces, including on Bloody Sunday in 1972, but says he never killed anyone. In 2010, a British inquiry into that shooting determined that British soldiers fired without provocation on the civil rights march in the city of Londonderry, killing 14 unarmed people. The queen, now celebrating her 60-year reign, was on the throne in those violent times. Her own family was not immune. In 1979, the I.R.A. killed her cousin Lord Mountbatten, who was also her husband's uncle. Handshakes cannot guarantee peace. But every move that breaks down old hatreds makes peace more durable. The Catholic nationalists haven't given up their goal of a united Ireland. But, these days, they aspire to achieve that eventually via the ballot box, not the gun.