Making London (or any city) better to live in is a good idea if it&#x27;s affordable, as is attracting more people to places that have a relative advantage in attracting investment and creating jobs. The terrorist argument doesn&#x27;t make much sense - London must already be pretty high up on the list of &quot;attractive&quot; terrorist targets based on all kinds of factors and I can&#x27;t see how a million or two more (or fewer) people is going to make much difference.<p>On the other hand, there&#x27;s an excellent argument for creating infrastructure outside London, it would be great to see a much stronger second city (or metropolitan region) - this would be attractive to some businesses that may be put off the capital by cost, relieve pressure on London, and be great for people for a multitude of reasons.<p>Given how cheaply governments can borrow money right now, I don&#x27;t understand why they&#x27;re not doing both, or why developed countries in general currently spend so little on infrastructure.