It seems to me that many of the responses are based upon preceived threat. Is this threat real? I see 3 historical reasons for invasion.
1. The vain glorious, done for personal glory, nationalism or to spread "gods word". This would include Chingis Khan, The Crusaders, Hitler and Japan in WW2
2. Need for land to live off. This would include the Anglo-saxon invasion of Celtic England and its subsiquent ethnic cleansing and the European invasion of Australia.
3. The desire for wealth. This incudes the Norman invasion of England which created the wealthest people the world has ever seen. The european colonialists didn't do too badly either.

How likely is any of this today.
1. These people arise randomly, but do they get far today. The Korean guy, Pol Pot and Saddam Hussan never got far. I think this kind of threat is very unlikely to persist today.

2. In search of land we have small groups, we call them refugees. They have no military capacity and are no threat. This could change if global warming brings big change but by then the US and other economies will have collapsed and little help would be forthcoming.

3. Why start something messy like a war when it is cheaper to buy and doesn't piss off the customers. Still there are fools like Bush. I don't imagine a MacDonalds franchise is worth much in Bagdad.
Ofcouse their are combinations.
So there is some possibility of threat but its not enough to base a whole relationship on. I feel we allow ourselves to be short changed by the US.
Instead we should be on good terms with all decent people and a good friend to those in need or those that just want to be friends. We also need a well equiped professional military to hit heads and a strong international police force to forefil our obligations. We have no need to tug the forelock, kow tow or any way debase ourselves to take our place in the modern world.

Whispering Ted, you say that "we should be on good terms with all decent people and a good friend to those in need or those that just want to be friends", which is all very charming, but what about the others?

What about the ones who, by our values, are not 'decent people' and who, for whatever reason, prefer car bombs to being friends?

You talk about historical reasons for invasion which (be they right or wrong) do not seem to address the threat from those who wish to destroy rather than to invade.

Ian to answer your question we must have a well equiped, well trained professional army and friends. Your second point is very valid, I exceeded 250words. Terrorism as Western Governments define it does not arise in a vacumn. It arises amongst down trodden, humilitated and unemployed young males. There are 25 million o these in the middle east, AIDS has prevented a similar build up in Africa. The phenomia is not Islamic, it is true that most of this group are in Islamic countries. Before the implosion of Bagdad the Tamil Tigers were the leading suicide bombers, secular Maoist comunists.
Defense from such people doesn't depend on USA, in fact they seem to create the conditions for more dispear and humiliation. Whilst we must defend ourselves from attack the long term answer is change the life conditions of young males. True the militery Industrial complex will not make money but it is cheaper than the present fiasco. We would preserve our personal freedoms although those that wish to rule by fear will not be happy.

With the decline of world standing, the USA is now being challenged on all fronts, but our defense problem remains the same, how to defend ourselves from Asian attack. I'm not just talking military attack here, but economic and cultural. The Americans like the Brits and Europeans are our cousins. When we chose to get into bed with the Yanks as opposed to the Brits, who withdrew from Asia, we chose a frontier nation like ourselves, still wet behind the ears. The Americans have made a real mess in their subsequent take over from Britain. Britain, had after all, centuries of experience in dealing with Asia and the Middle East. The blatant use of violence against America's opponents has increased animosity against them and made the world a more insecure place.
Britain has done well from its retreat from the pacific. The European common market is a tremendous success. They have a common currency, no borders for travellers and workers and a free flow of goods throughout the market. The cure to prevent a third European war has worked.
If the USA had sought to integrate its currency and markets with us and we had joined in an ecomic pact earlier and gone into it boots and all like the Brits did into Europe we may be in better shape. As it is we are nervous over American aggression and the fall out coming our way. We need to strengthen our relationship with NZ and as many others that can join in an economic trade zone like Europe. Only in this way can we avoid sliding into more violence.

I do not fear an Asian attack, its cheaper to buy the resources they need. As for cultural invasion, if I eat sushi rather than Big Macs I will be healthier. We are developing our own style, housing and foods that relate to the area we live in and evolve. This process has been delayed by us pretending we are another than what we are, an Asian/ Pacific nation.
I agree we need to start working on a regional union. Trade alone is not the basis of peace. European nations have traded with each other for centuaries but had little peace until the formation of the EU. What does bring peace and prosperity is interdependance