Leaders of the Irish republican movement have become accustomed to receiving a warm reception in Washington for St Patrick's Day, but this year will be different. Gerry Adams, leader of the political party Sinn Fein, is being given the cold shoulder on his trip to the US. President George W. Bush has refused to meet him, as has Irish-American Senator Edward Kennedy, a strong supporter of the republican case. The shift in US attitudes towards Sinn Fein is long overdue but it has been sparked by recent events. A bank robbery and a brutal murder have made it impossible to overlook the party's shady links with its violent paramilitary ally, the Irish Republican Army. For three decades, the IRA waged a terror campaign against Britain and members of Northern Ireland's majority Protestant community. It was responsible for bombings and assassinations. Today, these activities would surely mark out the IRA as a target in the US-led war against terror. But the republican cause has long enjoyed support - and funding - from Irish-Americans who share the dream of a united Ireland, free from British control. Times are now changing. The IRA has become a liability. A ceasefire agreement in 1997 laid the foundations for peace. Northern Ireland's future lies in devolved powers and a power-sharing agreement which the British government is still trying to broker. The IRA has stopped the bombings but has not laid down its arms or dispensed with its violent ways. It is blamed for a big bank robbery in December. But it is the killing of a Catholic man after a row in a bar in January that has done the greatest harm to Sinn Fein's reputation. The murder is believed to have been committed by members of the IRA. Sinn Fein is implicated in the cover-up that followed. The victim's fiancee and five sisters have caught the public's imagination with their courageous fight for justice. They - and not Mr Adams - are this year's honoured St Patrick's Day guests at the White House. The IRA made the situation worse by offering to shoot suspects it had identified as being involved in the killing. This appalling suggestion shows how little respect it has for human life - or the rule of law. The IRA has become no more than a refuge for mafia-style gangsters. It has no place in Northern Ireland's future. This appears to have finally dawned on the republicans' traditional supporters in the US. Now, it must also be recognised - and acted upon - by Sinn Fein. Irish people everywhere will celebrate St Patrick's Day tomorrow. Much of the world will join in, knowing the Irish to be a warm, friendly and charming people. Those in Northern Ireland deserve a better future. The peace process now may have enough momentum to win out. This will be more likely if the IRA - and its criminal ways - are consigned to history.