The war in Syria and the role of world powers in the conflict was addressed during the second debate between Donald Trump and Hillary Clinton on Sunday night.

Here is what the two US presidential candidates had to say on the raging Middle East war that has claimed more than 400,000 lives over the past five-and-a-half years.

Moderator: If you were president, what would you do about Syria and the humanitarian crisis in Aleppo

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Hillary Clinton: Well, the situation in Syria is catastrophic. And every day that goes by, we see the results of the regime by [Syrian President Bashar] Assad in partnership with the Iranians on the ground, the Russians in the air, bombarding places, in particular Aleppo, where there are hundreds of thousands of people, probably about 250,000 still left. And there is a determined effort by the Russian air force to destroy Aleppo in order to eliminate the last of the Syrian rebels who are really holding out against the Assad regime.

Russia hasn't paid any attention to ISIS [Islamic State of Iraq and the Levant - ISIL]. They're interested in keeping Assad in power. So I, when I was secretary of state, advocated and I advocate today a no-fly zone and safe zones. We need some leverage with the Russians, because they are not going to come to the negotiating table for a diplomatic resolution, unless there is some leverage over them. And we have to work more closely with our partners and allies on the ground.

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But I want to emphasise that what is at stake here is the ambitions and the aggressiveness of Russia. Russia has decided that it's all in, in Syria. And they've also decided who they want to see become president of the United States, too, and it's not me. I've stood up to Russia. I've taken on [President Vladimir] Putin and others, and I would do that as president.

I think wherever we can cooperate with Russia, that's fine. And I did as secretary of state. That's how we got a treaty reducing nuclear weapons. It's how we got the sanctions on Iran that put a lid on the Iranian nuclear programme without firing a single shot. So I would go to the negotiating table with more leverage than we have now. But I do support the effort to investigate for crimes, war crimes committed by the Syrians and the Russians and try to hold them accountable.

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Donald Trump: She talks tough against Russia. But our nuclear programme has fallen way behind, and they've gone wild with their nuclear programme. Not good. Our government shouldn't have allowed that to happen. Russia is new in terms of nuclear. We are old. We're tired. We're exhausted in terms of nuclear. A very bad thing.

Now, she talks really tough against Putin and against Assad. She talks in favour of the rebels. She doesn't even know who the rebels are. You know, every time we take rebels, whether it's in Iraq or anywhere else, we're arming people. And you know what happens? They end up being worse than the people.

Look at what she did in Libya with [late leader Moammar] Gadhafi. Gadhafi's out. It's a mess. And, by the way, ISIS has a good chunk of their oil. I'm sure you probably have heard that. It was a disaster. Because the fact is, almost everything she's done in foreign policy has been a mistake and it's been a disaster.

But if you look at Russia, just take a look at Russia, and look at what they did this week, where I agree, she wasn't there, but possibly she's consulted. We sign a peace treaty. Everyone's all excited. Well, what Russia did with Assad and, by the way, with Iran, who you made very powerful with the dumbest deal perhaps I've ever seen in the history of deal-making, the Iran deal, with the $150bn, with the $1.7bn in cash, which is enough to fill up this room.

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But look at that deal. Iran now and Russia are now against us. So she wants to fight. She wants to fight for rebels. There's only one problem. You don't even know who the rebels are. So what's the purpose?

I don't like Assad at all, but Assad is killing ISIS. Russia is killing ISIS. And Iran is killing ISIS. And those three have now lined up because of our weak foreign policy.

I think you have to knock out ISIS. Right now, Syria is fighting ISIS. We have people that want to fight both at the same time. But Syria is no longer Syria. Syria is Russia and its Iran, who she made strong and [Secretary of State John] Kerry and [President Barack] Obama made into a very powerful nation and a very rich nation, very, very quickly, very, very quickly.

I believe we have to get ISIS. We have to worry about ISIS before we can get too much more involved. She had a chance to do something with Syria. They had a chance. And that was the line. And she didn't.

I think Aleppo is a disaster, humanitarian-wise.

Moderator: What do you think will happen if it falls?

Trump: I think that it basically has fallen. OK? It basically has fallen. Let me tell you something. You take a look at Mosul. The biggest problem I have with the stupidity of our foreign policy, we have Mosul. They think a lot of the ISIS leaders are in Mosul. So we have announcements coming out of Washington and coming out of Iraq, we will be attacking Mosul in three weeks or four weeks.

Well, all of these bad leaders from ISIS are leaving Mosul. Why can't they do it quietly? Why can't they do the attack, make it a sneak attack, and after the attack is made, inform the American public that we've knocked out the leaders, we've had a tremendous success? People leave. Why do they have to say we're going to be attacking Mosul within the next four to six weeks, which is what they're saying? How stupid is our country?

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Look, I have 200 generals and admirals who endorsed me. I have 21 Congressional Medal of Honor recipients who endorsed me. We talk about it all the time. They understand, why can't they do something secretively, where they go in and they knock out the leadership?

I've been reading now for weeks about Mosul, that it's the harbour of where, you know, between Raqqa and Mosul, this is where they think the ISIS leaders are. Why would they be saying - they're not staying there anymore. They're gone. Because everybody's talking about how Iraq, which is us with our leadership, goes in to fight Mosul.

Now, with these 200 admirals and generals, they can't believe it. All I say is this. General George Patton, General Douglas MacArthur are spinning in their grave at the stupidity of what we're doing in the Middle East.

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Moderator: Secretary Clinton, you want Assad to go. You advocated arming rebels, but it looks like that may be too late for Aleppo. You talk about diplomatic efforts. Those have failed. Ceasefires have failed. Would you introduce the threat of US military force beyond a no-fly zone against the Assad regime to back up diplomacy?

Clinton: I would not use American ground forces in Syria. I think that would be a very serious mistake. I don't think American troops should be holding territory, which is what they would have to do as an occupying force. I don't think that is a smart strategy.

I do think the use of special forces, which we're using, the use of enablers and trainers in Iraq, which has had some positive effects, are very much in our interests, and so I do support what is happening, but let me just…

I hope by the time I am president that we will have pushed ISIS out of Iraq. I do think that there is a good chance that we can take Mosul. And, you know, Donald says he knows more about ISIS than the generals. No, he doesn't.

There are a lot of very important planning going on, and some of it is to signal to the Sunnis in the area, as well as Kurdish Peshmerga fighters, that we all need to be in this. And that takes a lot of planning and preparation.

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I would go after [ISIL leader Abu Bakr] Baghdadi. I would specifically target Baghdadi, because I think our targeting of al-Qaeda leaders - and I was involved in a lot of those operations, highly classified ones - made a difference. So I think that could help.

I would also consider arming the Kurds. The Kurds have been our best partners in Syria, as well as Iraq. And I know there's a lot of concern about that in some circles, but I think they should have the equipment they need so that Kurdish and Arab fighters on the ground are the principal way that we take Raqqa after pushing ISIS out of Iraq.

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Source: Al Jazeera News