Let’s say the UK and someone in Australia’s neck of the woods were going at it, and the UK was (for whatever reason) at a disadvantage in that conflict. Is Australia obligated in any fashion though treaties or other agreements to defend or protect the UK’s interests.
Would Australia automatically take the UKs side in any conflict?
If we were having a go at NZ you can betcha those Aussies would be right behind us. 
On a serious note the answer is yes the Australians would back us just as we would them.
I think the only mutual defense treaty that Australia and the UK both belonged to was the Southeast Asia Collective Defense Treaty which created SEATO, and is now defunct. Australia and the UK have been involved together is some military action (most recently in the Iraq War), and both have mutual defense treaties with the US (ANZUS and NATO, respectively), but neither is bound to aid the other. For example, Australia was not involved in the Falkland Islands War.
Probably not, since Australia and New Zealand have a mutual defence treaty, ANZUS.
Prior to Australia’s adoption of the Statue of Wesminster (1931) in 1942 (retroactive to 1939) a declaration of war by the sovereign on the advice of British ministers bound Australia. It was the same for all dominions before the SoW.
Not only has the Statute of Westminster changed things, but countries don’t declare war these days. I suspect that the last time either the UK or Australia declared war was back in 1941, against Japan – and that war is long over.
There are no treaty obligations, and the gap between British and Australian politics has widened immensely since 1945. Our turning our backs on our old Imperial trading partners by joining the European Common Market in 1973 was a real slap in the face for them and they’ve had to work hard at finding new markets for their exports. Whilst the Crown connection endures, I don’t think it will last many more years beyond the present reign.
Out of curiosity in a conflict against a regional power what could the Australians bring to the table re military horsepower? Are they so buffered/isolated being an island that the distance to strike them is their main defense?
We have a smallish (well, probably ok for our size) but mostly modern defence force. Our soldiers are very well trained, but there aren’t enough of them. We have a few expensive new pieces of hardware and quite a few more beat up old ones. Australia has never single-handedly invaded anywhere, so I don’t know what we are and aren’t capable of in that regard, but in places like Iraq where we have been part of a larger force, we can certainly turn out a bunch of soldiers, a few Blackhawks, a warship or two, some fighter jets… I guess we’re a second or third level military power - not the UK, US, or China, but we ain’t Botswana either.
Yes. Although, being an island is only part of it. A lot of it is being a freakin’ HUGE island which presents its north face to the nearest neighbours, huddles all its cities in the far south, and plonks several thousand miles of inhospitable desert in between. I have heard it said that the only country which could successfully invade Australia alone is the US. I find that a bit far-fetched as I think there might be one or two others with a shot at it, but basically it wouldn’t be easy. Australia is nothing like a military superpower, but we would be able to pull significantly above our weight if our own soil was invaded. Logistics are on our side.
New Zealand forces would be there to assist us before we even picked up the phone to ask. The US almost certainly would. The UK likely would do something.
To answer the question more directly, yes the US is, as far as I know, obliged to assist us, and we are obliged to assist them (against attacks on home soil - not actions like Iraq). As Mk VII said, we have drifted apart from the UK politically, and those few old fashioned Australians who make the big trip to the “Mother Country” get a rude shock at Heathrow when they are forced to line up with the “Aliens” and watch the Germans getting through Immigration faster. Personally, I don’t blame the UK one bit for this. Relations between the UK and Australia these days are cultural rather than political, and we’re still rather fond of one another, although this is less about politics and more about watching one another’s bad soap operas. The UK would likely assist Australia, but for no other reason than that it would be the “done thing”. As far as I know, they are under no obligation to assist.
WWII-style didn’t the Australians have a scorched earth policy to lengthen Japanese supply lines to unsustainable levels, were an invasion to happen?
There’s plenty of countries in a similar position. And in a similar way to Australia’s major role in East Timor, other countries have provided peacekeeping forces elsewhere.
We get Neighbours (indeed the only reason this programme still exists is 'cos the BBC pays for it) and Home and Away. What on earth are you lot watching?
Yeah. That’s why it’s hard to predict what would happen. We’re a sort of middle to small level Western power along with many similar countries. Our case is more confused for geographical reasons. You could compare the Australian defence forces to those of several European countries in terms of numbers and amount of hardware, but the specialities are different. I would wager that for example, the ration of support ships and aircraft to combat ones is probably more skewed towards the former here and the latter in Europe. We specialise in logistics and supply because we need to, and a European country would be better off specialising in rapid response.
East Enders was on for years and years. No idea if it still is. We were also burdened by Birds of a Feather and that thing about the 1960s country copper, the name of which escapes me.
Why do our two countries insist on subjecting each other to this stuff? Maybe we’re not allies after all!
Heh heh, it’s “Look at our ancient heritage” vs. “Look at those hot surfing teens!”.
New Zealand getsCoronation Street and Australia gets The Bill as well, I think.
The ‘Brisbane Line’ was a controversial plan that was much criticised (in retrospect) for abandoning much of Northern Australia to the invader
Heartbeat.
We also get “A touch of Frost” and Corrie and Rosemary and Thyme and all of those other “Drama-Soap-Batty old lady in a country village investigates Gubbins” style programmes.
The ABC is to blame for a lot of that.
The US, in the person of General MacArthur, had a plan to abandon the northern half of Australia down to the notorious Brisbane Line . Wiki claims the then Prime Minister Robert Menzies originated the plan but I’ve not heard that side of it before. It did contribute to his losing office in the middle of the war though.
Difficult to cite, but it’s worth noting that were Australia attacked or left significantly at risk in a conflict, there would be huge public pressure on the UK government to get involved. Almost everyone knows someone who has emigrated out that way, and there are loads of Aussies over here. Plus there is the historical/cultural thing, and a lot of people would see it as an attack on our own.