peteblue
Welcome back Wayne
This is another popular misconception about the IRA mate. The IRA are not sectarian if anything they are very left socialist. Many of the IRA founding members and most prominent members were Protestant. The IRA actively canvassed the Protestant areas of NI for members.
The IRA are political, they are not sectarian, of course much of the discrimination by Unionist and British forces fell on the Catholic community so there is a natural alliance there and it produced breeding grounds in terms of nationalism.
But by nature the IRA would and have welcomed any nationalist regardless of religion.
British forces were deployed to protect catholic communities and were welcomed when they arrived, unless my memory is playing tricks....