It is cowardly because it flouts the nature of conventional war. Millions of civilians have died in past wars but terrorism has made them specific targets. The underbelly of a society. The weakest link strategy, that bypasses a nation's conventional military.

This is not to excuse the bombing of cities in war. But, the modern terrorist has no need for an army or the expensive hardware of war. Just a bomb, or a plane. Even a knife. The terrorism strategy was played out brutally at the Munich Olympics in 1972 when Palestinian terrorists murdered Israeli athletes. It shaped the tragedy of the 9/11 World Trade Centre attacks and the Bali bombings.

Apologists for terrorists describe the actions as akin to the French resistance in World War II or the so called freedom fighters of the IRA. But no. Such a pathetic excuse is an insult to the French resistance. They targeted an occupation army. The IRA and more recently Islamic terrorists by definition have targeted innocent civilians as hostages and victims of political terror.

Some may argue that the events in Sydney yesterday are a direct consequence of Australia's involvement in the fight against terrorism in the Middle East and Afghanistan. The argument goes that if Australia withdrew from these engagements we would not be a target.

The Bali bombings put the lie to that argument. It is in Australia's interests to preserve political and economic stability in the oil rich Middle East. We also have a moral obligation to protect thousands of innocent civilians from the totalitarian, murderous path of the Isis organisation.

The same people who would want Australia to withdraw from this campaign also accuse Australia of abandoning refugees. They can't have it both ways.