US naval blockade explained: legality, risks & impact on global shipping routes

[0:00] listed in maritime law and security at the University of New South Wales. And she's also [0:03] a former naval officer. She joins us now live from Canberra in Australia. Jennifer, thanks for being [0:09] with us here on Al Jazeera. We appreciate your time. Let me ask you first, how would the U.S. [0:14] Navy carry out this blockade in practical terms? And what are the legal concerns? Would this [0:20] potentially break maritime law? Hey, thanks for having me on. Now, I'll address the legal concerns [0:28] first. Now, the U.S., Israel and Iran are in an international armed conflict. So when you're [0:32] in an international armed conflict, the conduct of that conflict is governed by both international [0:37] humanitarian law, law of armed conflict, and a subset of that, which is the law of naval warfare. [0:42] Now, in an international armed conflict, a blockade is a legal method of war. So naval blockades are [0:48] lawful in that context. But there are certain conditions. So the first one is that it can't [0:53] adversely impact neutral states. So they couldn't blockade the Strait of Hormuz, for example, [0:58] because that would impact the states inside of the Persian Gulf. Two, you need to allow food through [1:04] and you can't adversely impact the civilian population. You can't starve out the civilian [1:08] population. Three, and this is important, it needs to be impartial. So you'll note that when CENTCOM [1:13] have announced this blockade, different to President Trump's comments, they have said it will apply to any [1:18] ship of any flag going in and out of Iran. And that's important. It has to be impartial for [1:23] it to be a lawful blockade. So for all of those reasons, this is actually a lawful method of [1:28] warfare to generate economic leverage in a conflict. Jennifer, I've seen some analysts already saying [1:34] that this blockade or threat to blockade, that it may not affect more than a handful of vessels [1:39] that are still attempting to navigate the Strait, at least for now. Is that take in line with your [1:44] thinking? Look, it'll affect any vessels that do try and take goods out of Iran, including oil, [1:52] any vessels that try and resupply Iran. And you've got to think about in this conflict, [1:57] the US has not stopped Iranian oil flowing. In fact, the Strait hasn't been closed. Shipping [2:02] has been deterred from going through. But normally you'd have 130 ships going through a day. We [2:06] haven't seen that. We've averaged three and a half ships a day. But of the ships that have gone [2:10] through in the last six weeks, it's been about 130. Most of those have been ships going to and from [2:15] Iran. Now, the US has allowed that to happen. In fact, early in this conflict, [2:19] the US reduced sanctions on Iranian oil. So this is about applying freshers. So it will be any ships [2:24] that are coming out of Iran or going in. The second objective of it is there have been rumours [2:28] around, certainly reported in some US media, that China or certainly US intelligence thinks that [2:33] China is going to try and resupply Iran with anti-air missile defence, so shoulder launch missiles, [2:40] for example. Now, this would stop any military resupply of Iran by countries such as Russia and China [2:46] through the maritime domain. Now, how many vessels it will be, it really depends on how many vessels [2:50] try and run that blockade. It is important that the US has said that this will be any vessel of [2:55] any flag trying to do that. We can see from those two examples I've given, they're trying to isolate [3:01] Iran from any military resupplies and trying to put economic pressure on Iran by intercepting oil [3:06] flows and other things. Jennifer, are there risks at this stage that the US could intercept the vessel [3:11] of nations that aren't involved in the conflict? And what would that mean? So the US will likely [3:18] intercept vessels of nations that aren't involved in a conflict. Now, again, under a blockade law, [3:24] any vessel going to and from that country, no matter where it's registered, no matter where it's flagged, [3:29] is allowed to be stopped and boarded and searched. So there are a number of either flags of convenience, [3:35] so ships flagged to countries that have no real connection, or ships flagged to countries that are [3:41] friendly with Iran that do supply Iran. So it's not just Iranian ships, it will be any ship of any [3:46] flag going to and from Iran. Now, of course, there is the risk there of escalation. But I would say [3:53] that without applying some degree of pressure on Iran, and this is a much better option than [3:57] bombing Iranian infrastructure, for example, that would have long term economic impacts that would, [4:03] you know, struggle to rebuild it. This is a way of putting pressure on Iran to achieve those aims [4:08] that the US stated in the first week of the conflict. Jennifer, you say, of course, [4:11] there is risk of escalation. Based on that, do you think that at this stage, most shipping companies [4:16] would basically rather wait and see if there's any kind of tentative peace agreement before they [4:21] attempt to navigate the strait? Well, I think it's kind of two different elements. I don't think [4:26] the shipping companies will be concerned about the US's announcement of a blockade. I actually think [4:31] that most shipping companies will find this positive. The reason shipping companies have not been [4:36] going through the strait is not because it's closed. It is not closed. It's not blockaded by [4:39] Iran. But because they've assessed that the risk is too high. To encourage ships to go through that [4:44] strait, the US needs to be able to reassure them that it's safe to do so. The transit of the two [4:49] destroyers on Sunday was part of that reassurance campaign. Getting mine clearance assets in that [4:54] strait, whether there are or are not mines there, will also be part of that. And communicating to the [4:58] shipping community of what is going on will be part of that. So I actually think the general [5:03] international shipping community is probably quite happy about this announcement as opposed to [5:06] concerned. Will that mean you see ships going through the strait? No. I think that there are [5:11] a number of layers of that reassurance campaign. But if we continue to see US naval presence, if we [5:16] don't see any more Iranian attacks on merchant shipping, if the US manage to either confirm there's [5:22] no mines or clear mines, that's when you'll start to see ships start to flow back through. And so I think [5:26] this was an important step in that reassurance campaign. All right. Jennifer Parker is a specialist in [5:32] maritime law and security at the University of New South Wales. She's also a former naval officer. [5:37] She's joining us there live from Canberra in Australia. Thanks so much, Jennifer.