Catholic population had recently begun a civil rights movement to try getting the world to notice that they were being treated unfairly. During the Craigavon Bridge incident in October 1968, the Catholic marchers approaching the bridge where confronted by the RUC by pushing the marchers back with water cannons and assaulting them… After the Burntollet Bridge incident in January 1969 where RUC officers made little attempt to protect the marchers against loyalist mobs, 80 people’s Democracy marchers were taken away. Lastly at the Battle of the Bogside in August 1969 RUC officers and B-Specials helped the loyalist mobs by removing the barricades set up by the Catholic-bogsiders… All of these events made the Catholic community feel isolated and unprotected. Therefore they started calling for their own protective force or vigilantes against the RUC and B-Specials. This was therefore the official reason for their arrival: protect the Catholic population against the Loyalist attacks. The Catholics welcomed them by making them tea, sandwiches and even attended army parties; on the contrary they received a hostile welcome from the Protestants. Despite this, the army was seen as a neutral force.
The fact that the Catholic communities felt abandoned and with no support meant that the IRA re-emerged as a major force in Northern Ireland to help them. This made the British secret intelligence believe that the IRA was about to launch an uprising in Belfast and Londonderry through Protestant areas. The government therefore sent the troops [unofficially] to prevent this.
Privately the British government knew that a number of disorders across Northern Ireland were occurring between the different Protestant and Catholic communities and that the 3000 RUC couldn’t cope any longer, they had lost control of the situation. The Catholics had started campaigning for civil rights in 1968, due to the discriminations they faced in employment, housing, education, cultural and political involvement throughout the day. This provoked violent reactions within the Protestant community. The army had to help restoring law and order on the streets.
But the most important reason was that Northern Ireland appeared to be on the brink of civil war and the British government wouldn’t let some part of its land to be on a civil war before having tried preventing it. They had to try to reach an accord between Protestant and Catholic communities to prevent what seemed as inevitable. Although the government had already considered sending troops for a number of years and had already placed large number of soldiers on standby since April 1969…
Although, the real reason has never been ascertained; The official one didn’t prevent the army from being drawn into violent conflicts within the next years; Entire Catholic communities lost faith in the RUC and the N.I. government. This lead to a civil rights movement, which was fuelled by enormous discontent and hatred towards the British rule. Consequently, the IRA emerged as the unofficial guardians of Catholic communities against RUC and loyalist mobs.
