You have to have as many defences in place as you possibly can. But even then of course - and it's important to stress this - you cannot guarantee being able to prevent every attack or every kind of attack.
I'm going to reduce the size of the Cabinet, cut the number of ministers, reduce the size of the House of Commons, campaign for a European Parliament with 100 fewer members, halve the number of political advisers, and abolish a huge swathe of Labour's regional bureaucracies - and agencies and their offices in Brussels.
The appalling crackdown that we witnessed in Hama and other Syrian cities on 30 and 31 July only erode the regime's legitimacy and increase resentment. In the absence of an end to the senseless violence and a genuine process of political reform, we will continue to pursue further EU sanctions.
Today further EU targeted sanctions on Syria come into force. The message is clear and unambiguous: those responsible for the repression will be singled out and held accountable.