Donaldson stated in Richard English's book, "Armed Struggle": "A big part of the motivation for me in becoming actively involved in politics was the deep sense of injustice that I felt had been perpetrated against my people and specifically against my family and I wanted to do something about that. And that's why, at the age of 18, I did two things, I joined the Ulster Defence Regiment and I joined the Ulster Unionist Party, because I wanted to pursue, through the forces of the state and the forces of law and order, the IRA and to oppose their campaign. But I also wanted to be involved politically in opposing that campaign as well".