Generally, it reminds me somehow of barbarians invading the Roman Empire.
The Empire has not fallen just because of military purposes, but once the Romans accepted the incursion of the barbarians the case was lost and just the matter of time before they became minority in their own land. And the barbarians didn`t take accept much of the civilization - most of it got lost very soon
And the very guy, well, I`m not British so I won`t comment his statements.