"It is not easy to forget that the clash between the Nirankaris and the Sikhs played a major role in touching off militancy in Punjab. Terrorism may be dead now, but the religious extremists are still around, always ready to exploit a situation. All political parties have in the past courted the Dera during elections because it has potent vote-bank. These parties would be doing signal service to the people if they got together to work out a compromise after which the issue could be debated in calm and rational manner. Bhinderwale's legacy that claimed the life of a Prime Minister still haunts India. We cannot afford another round of violence. " In the above para, what is the meaning of (1) touching off militancy and (2) signal service.
touching off = setting fire to. Fireworks have a 'touchpaper' - you light it, it smoulders for a few seconds, and then the pyrotechnics start. So 'touching off militancy' is provoking an outbreak of violence.
signal = very noticeable. This is a very rare meaning, which exists chiefly in the phrase 'signal service'.