Simplify the following text for a Grade 9 native English-speaking person.
Original: If this happened , an Irish Boundary Commission was to be established to redraw the Irish border , which Collins expected would so reduce the size of Northern Ireland as to make it economically unviable , thus enabling unity , as most of the unionist population was concentrated in a relatively small area in eastern Ulster .
Simplified: If this happened , an Irish Boundary Commission was to redraw the Irish border .