After recent riots, the British government has sent 2,000 troops back into Northern Ireland and has resumed military street patrols for the first time in two years. The riots were sparked when the government refused to allow the annual march of the Protestant Orange Order through the Catholic town of Portadown. This march, carried on for decades as a means of demonstrating to Catholics that Protestants run the province, has become extremely controversial over the last few years.--Stephen V Cole