OK, so immigration and asylum laws are complex, and policy is too. My own view is rather nuanced, and I tend to think anyone who is too absolute in the area is kidding themselves and heartless in different ways.
There is one thing that's pretty much absolute, though, and it's called 'Non-Refoulement'.
Basically, it is the core of refugee law and policy, and it has a few different little bits and pieces associated with, but at the core of this core point is this:
YOU CANNOT RETURN PEOPLE TO A PLACE FROM WHICH THEY FLEEWITHOUT ENSURING THAT THEY ARE NOT AT RISK OF PERSECUTION, THE DENIAL OF FREEDOMS AND RIGHTS, OR DEATH, BASED ON RELIGIOUS, ETHNIC, POLITICAL, OR SOCIAL IDENTITY, UNLESS THEY POSE AN UNACCEPTABLE RISK TO THE WELLBEING OF THE COUNTRY TO WHICH THEY FLEE.
...and even then, efforts should be made to send them to a third party state ideally, but nobody really ever bothers with that.
Not everyone who seeks asylum is at risk of persecution. But everyone who seeks asylum has the right to have their claim investigated.
On the one hand, these people did not actually arrive in Australia, although they did enter our area of control (the 'migration zone' is a farce, and in general we should ignore it - if we exercise power over a claimed ocean territory, it comes with being part of the migration zone obviously - but let's accept that it is not), and so it is slightly murkier than if they crossed a land border. Many also originally went to India before embarking en route to Australia, and an argument could be made that India was the first point of refuge, and therefore Australia has no obligation to do anything but return them to India.
Let's be generous to the government, and assume they all went to India first and that was the first point of refuge for all of them, and ignore questions over whether it is a true point of refuge if India hasn't signed the Refugee Convention. So, we're going to be returning them to India, yes?
Problem is, India won't take them. Sure, we could find a way to drop them off there, but the diplomatic repercussions would be exceptional. India's already dealing with a significant number of refugees from pretty much every country in the region, from Burma to Tibet to Afghanistan, alongside Sri Lankan refugees, so I can understand their reticence.
I think everyone agrees we can give the forcing-them-on-India option a pass, so we're left with two options.
1. You process them in your own facilities. My own view is that this should be a reasonably quick process in detention in Australia, but let's accept for a minute that years and years in territories other than those in which they intended to seek asylum is without problems. At the end of the day, Nauru might not be paradise, and it might not be safe, but it is a point of refuge of a sort. Even if it's essentially prison and the denial of rights and freedoms without having committed a crime and with an indefinite period of processing... even if they're children who are self-harming and losing all hope after months and years growing up inside cages...
2. You return them to the country from which they were originally fleeing without adequately processing them.
In essence, we've chosen the second, and attempted to call four questions asked by phone while desperate people were on a ship of war surrounded by people in uniform in the middle of the ocean adequate.
This is an insult to law as much as to morality. But let's even accept that it was adequate (I know, hard to do, but try).
Anyway, Australia chooses to return them to the country from which they are fleeing after we *cough*in-*cough* adequately processed them.
Where they were immediately arrested and put in gaol. Thumbs up!
BUT, of course, they weren't put in gaol for their religious, ethnic, political, or social identity, of course! They were locked up for leaving Sri Lanka through unapproved means! This is totally not about anything else!
So, we've accepted a few things here.
We also haven't dealt with whether or not they pose a significant threat to the wellbeing of Australia, but that'd add another 500 or so words and nobody fully understand these people's particular circumstances or risks, so let's just assume that they may well be threats.
Here's what we've accepted so far:
1. They all left from India.
2. India was the first point of refuge.
3. They did not enter Australia's area of responsibility (even though we exercise power over the area).
4. Even so, we took it upon ourselves to assess their claims.
5. Some, even all, of them may be risks to the wellbeing of Australia.
6. Indefinite offshore detention is a-ok.
7. Even for children.
8. Even for children who are self-harming.
9. We can't just force India to take them.
10. We processed them adequately by asking them four questions on a boat in the middle of the ocean after telling them we would never be offering them asylum in Australia, no matter what.
11. There is no reason to believe that they are at significant risk of persecution in Sri Lanka. Hell, most of them were Sinhalese anyway!
12. When we handed them over to Sri Lanka and they were immediately imprisoned, it was irrelevant to their asylum claims.
Hard to accept a lot of that, but I hope you're still with me.It's still illegal.
Immoral bordering on evil too, but let's accept that morality has nothing to do with this issue and keep it strictly law.
Under international law, we are required to return a boat in distress to the nearest port, or one of our own ports, or the port from which they departed. I'll admit this isn't an area of expertise for me, but that's the crux of it.
If it wasn't a boat in distress, we boarded a boat with force, against the wishes of the operator of the vessel, and are pirates.
Anyway, basically, even if you turn off your heart and accept a lot of really questionable things, we're still acting illegally. But are we still in breach of our obligation of non-refoulement?
Depends who you ask. If you ask 53 legal scholars from 17 Australian universities, we are. If you ask Scott Morrison, we aren't.
If you believe, as the scholars do, that "Holding asylum seekers on boats in this manner also amounts to incommunicado detention without judicial scrutiny", then yep.
But let's even accept that that's wrong, and we've cleared the legal hurdles.
Here's the Minister:
"This is how you stop the boats. This is how it has to be done because this is what works".
So, the government has stopped the boats. Other than the other one that they're going through all this with at the moment.