THE callous killing of two British soldiers and a Northern Ireland policeman in the past few days has brought back vividly to our memories the times not so long ago when such killings were almost routine in character. Whatever motive may have been in the minds of those responsible for these atrocities, they cannot have expected the united front displayed against them by the Northern Ireland's leaders and their communities. Symbolic of this stand was the Rev Ian Paisley's praise for Father Tony Devlin, a Roman Catholic priest who conducted a special service at his church during which he condemned the killers. “There is grief,“ said Paisley, “but there is also being born a new spirit of unity that we have never seen before.” Another figure to emerge impressively from these events has been Shaun Woodward, the Northern Ireland Secretary, who has spoken plainly and uncompromisingly about the general determination not to lose any of the progress made towards a peaceful society since the Good Friday Accord was struck almost eleven years ago. There must be a robust response to this week's killings but it must avoid any semblance of a return to the times when security measures often exacerbated rather than healed community tensions. Northern Ireland must retain and build on all the gains that have transformed it in recent years.