Just to point out that it'd have to cross a lot of heavily guarded airspace before it reached the UK. A straight line from the westernmost part of Iran to the UK goes over the Eastern flank of NATO, namely Romania and Poland, which is very much set up for air defence (albeit with Russia in mind)
Certain aspects of the media are treating this as clickbait. There are not swarms of Iranian missiles likely to be heading to London.
Which would be useless with the missile in an ICBM role
Also, of the two missiles fired, one failed part the way there ( possibly it ran out of fuel? ) and the other was shot down a long way before it got anywhere near Diego Garcia - so not just a firework, but a damp squib...
Was one really shot down? In any war including this one, truth is the first causality.
With a missile that uses a ballistic trajectory, it's not easy for an interceptor missile to successfully damage it throughout the entire flight. So how effective an interceptor missile may be does depend on where the ballistic missile is at the time. The speed of the missile is also a factor, as it's much harder to intercept at faster speeds.
A "long range" ballistic missile at the highest point of it's flight travels very high up in the upper layers of the atmosphere or even beyond that into space, making it very hard to intercept during this part of it's flight.
And in the terminal part of the flight, as the speed reaches maximum, that's also a difficult part of the fight path for a interceptor missile to hit a ballistic missile.
So it's unlikely that a ballistic missile aimed at the U.K. flying very high over the European mainland would be intercepted during the highest part of it's trajectory.
Having said that, I don't think Iran will target the U.K. mainland.
