Problem with what Corbyn has said is that implies he's willing to change foreign policy as a direct result of the slaughter of children in Manchester. That would be a massive boost for the terrorists and encourage more attacks across the West. I don't think anyone is defending the decision to invade Iraq anymore, it's clear it was a disaster and the people responsible should be held to account (but unfortunately never will), likewise Libya. It's time to face facts, we are losing this clash of cultures between Islam and the West - we need to up our game to have any chance of reversing that, and I don't think Corbyn is the man to do it. Corbyn voted against thirteen key pieces of anti-terror legislation let's not forget.
Edit: Some other inconsistencies with Corbyn's position:
1) If intervention causes terror, why did the interventions in the former Yugoslavia, Serbia and Sierra Leone not result in terror attacks by the people we intervened against?
2) Why have France, Germany, Mali, Central African Republic, Nigeria and the Philippines, who did not take part in the 2003 invasion of Iraq, been targets of Islamic terrorism?
3) Why has Poland, who did take part in the 2003 invasion of Iraq, not been affected by Islamic terrorism?