ABC News’ Kirit Radia reports: There was a sober tint, not seen in years, to this year’s St. Patrick’s Day celebrations in Washington, D.C. when Irish leaders came to mark the day with at the White House. Amid Secretary of State Hillary Clinton’s shamrock lapel pin and jokes of a "President O’bama," last week’s deadly attacks in Northern Ireland cast a noticeable shadow over today’s events. But unlike past attacks, it appears this recent violence may only galvanize the once-warring sides who now look only to Northern Ireland’s future. "They intended to divide us. They intended to drag Northern Ireland back into conflict," Northern Ireland First Minister Peter Robinson, a Protestant, said today. "They have not succeeded and they will not succeed." "We don’t speak about two communities; we represent — although we represent different parties, we represent one community in the north of Ireland. And we are not going to allow our community to be plunged into mayhem and destruction by people who have no support, no mandate whatsoever," Deputy First Minister Martin McGuinness, a Catholic, concurred. "The institutions are, in my opinion, stronger and more stable now in the aftermath of the three killings then they were before," he added in a confident Irish lilt. Since the Good Friday Accords were signed in Belfast almost eleven years ago, the power sharing agreement has brought peace and economic prosperity to the island. The two leaders are touring the United States in search of American private investment in their region, and appeared determined not to allow the attacks to derail their lofty economic goals. "We want to go up the food chain in terms of the type of jobs that we have in Northern Ireland. We’re looking at high-end engineering, financial and business services, IT, creative industries. Those are the areas that we are wanting to grow in Northern Ireland," Robinson told reporters. The United States again appears ready to ensure the peace holds. "Recent acts of violence cannot be allowed to undermine that progress and the progress that is yet to come as these two leaders and those who work with them continue to move into the future," Secretary Clinton told reporters, standing alongside Robinson and McGuiness after their meeting at the State Department. The Obama administration has yet to appoint an envoy for Northern Ireland, but today Clinton told reporters one would be named at an unspecified date. "We’ll be appointing someone who will pay attention to the economic investment side of this," she said, as Robinson and McGuinness nodded enthusiastically in approval. "We will leave Washington incredibly buoyed up by the encouragement and support that we’ve received here," McGuinness declared.