^ I wouldn't necessarily say that. One man's "Terrorist" is another's "Freedom Fighter". It does largely rely on public sympathy though, and after 9/11, such sympathy was going to be in short supply.
Though no to the question. Firstly, those within the UK had always considered the IRA's attacks as atrocious, and whilst US sympathy may have been sort after, it wouldn't have been that much of a decisive influence I don't think
Secondly, I don't the timelines don't really equate. Calls for and agreements for disarmament were made both before and after 9/11 (was it 2005 they actually got round to it?), as far as I'm aware there isn't much to say that the IRA doing so was directly influenced by it.
That's a silly statement. "9/11 gave terrorism a bad name". Terrorism CAN'T be a bad thing, otherwise why would our tax dollars support it? Why would we be offering terrorists amnesty in Miami right NOW? Terrorism is awesome. I know that for a FACT, because America supports it, so it can't be bad.
Oh, wait. Hang on. I just looked it up. It looks like I got 'terrorists' and 'freedom fighters' confused again. That ALWAYS happens to me. Sorry. Just because they commit the exact same sort of atrocities, I keep getting confused about which ones are the ones that are good, and which ones are bad. I'll have to remember it.
Kill thousands of civilians to get people to cast of a leftist government - freedom fighter. Kill thousands of civilians to get people to cast off a right-wing dictatorship that's cozy with U.S. industrial interests: terrorists.