>Did each bombing of London bring the IRA closer defeating the British?
The IRA's goal was never to "defeat the British", it was to force them out of Northern Ireland and unite the island of Ireland in one nation. After the Good Friday Agreement, the British withdrew troops, gave up many governing powers in Northern Ireland, and laid the constitutional framework for a potential future referendum to unite Northern Ireland and the Republic of Ireland in a single nation. In short, the PIRA got most of what they wanted. The Good Friday Agreement was an (largely successful) attempt by both sides to end The Troubles, so to claim that the PIRA was unsuccessful is a bit disingenuous.
You should also note that if the majority of people in Northern Ireland wanted to be part of the Republic they would actually vote that way at any of the relevant elections.
Having said that, the minority community in NI had been treated pretty awfully over the years so I think the current situation is a pretty decent compromise.
The IRA's goal was never to "defeat the British", it was to force them out of Northern Ireland and unite the island of Ireland in one nation. After the Good Friday Agreement, the British withdrew troops, gave up many governing powers in Northern Ireland, and laid the constitutional framework for a potential future referendum to unite Northern Ireland and the Republic of Ireland in a single nation. In short, the PIRA got most of what they wanted. The Good Friday Agreement was an (largely successful) attempt by both sides to end The Troubles, so to claim that the PIRA was unsuccessful is a bit disingenuous.