This year we commemorate the fourth anniversary of the terrorist attacks in New York and remember the 3,000 victims that lost their lives there, including 10 Australian citizens, as well as the dozens of thousands who suffered damages. The September 11 events were an attack against our way of life. The attacks in Madrid, Bali, London, Jakarta and Iraq are the continuation of that combat.
In spite of those attacks, democracies are developing around the world and that is why Australia reaffirms its commitment in Afghanistan and Iraq. Since September 11, 2001, we have been working to improve our legislation to fight terrorism and to increase the security of our public facilities. This reminds us of the threat that is upon us.
After the September 11 attacks, the provisions of the ANZUS Treaty were invoked for the first time in 50 years and Australia is participating in the war against Al-Qaeda and the Talibans developing its means of defense against terrorism. Since September 11, 2001, our concept of terrorism has changed.

Source
The Age (Australia)

Attacks changed our lives”, by John Howard, The Age, September 10, 2005.