美国进行了所谓的对也门胡塞控制区的五个目标进行自卫打击五角大楼表示，自红海和亚丁湾袭击开始以来，胡塞武装首次使用无人潜艇。
美国广播公司新闻频道(ABC News)国家安全和国防分析师、前五角大楼官员和中央情报局特工米克·马尔罗伊(Mick Mulroy)表示，这艘无人潜航器(或称“UUV”)显示出胡塞武装能力的提升和战略的转变。
“无人水面和水下船只可能比空中无人机和反舰导弹更难发现和摧毁。胡塞人不太可能自己制造这些武器，所以它们很可能来自伊朗。
除了周日遭到袭击的无人潜艇外，美国军方表示，它还袭击了一艘在水面上移动的无人船只，以及反舰巡航导弹，这些导弹构成了美国在胡塞军火库中的主要目标。
胡塞武装在也门内战停火后，在他们控制的也门部分地区活动。美国将胡塞武装列为得到伊朗支持的全球恐怖组织。美国说，国际革命卫队(IRGC)圣城军(Quds Force)为胡塞和其他武装组织提供武器和资金支持。圣城军是伊朗政权军事力量的一个分支，负责协调伊朗境外的行动。
穆尔罗伊说:“胡塞武装和IRGC正在调整他们的战略，显然是因为他们没有成功袭击美国海军舰艇。”胡塞武装以美国船只为目标，但没有成功。自伊朗支持的另一个民兵组织袭击美国在约旦的基地并杀死三名军人以来，美国一直在增加防御性打击。
穆尔罗伊说:“如果这些武器中的一件或多件穿过并杀死了美国水兵，伊朗应该承担直接责任。”
穆尔罗伊说，无人武器系统是一个严重的威胁，因为它们可以通过从多个维度进行攻击，即所谓的“群体攻击”，来“摧毁船只的防御”
美国海岸警卫队表示，他们在1月15日拦截了一艘从伊朗驶往胡塞控制的也门的船只上的一批武器。美国表示，被截获的军事设备中包括无人驾驶船只的部件——这种船只在周日的两次美国袭击中受到了打击。
一名美国官员告诉ABC新闻，作为美国对胡塞侵略先发制人攻势的一部分，美国对伊朗间谍船MV Behshad进行了网络攻击，该船在红海巡航并向胡塞传递目标信息。这次网络攻击是1月28日约旦民兵袭击后几天美国承诺的多层次回应的一部分。
胡塞人周一表示，他们在过去24小时内进行了五次袭击。胡塞武装在一份声明中称，两艘美国船只在亚丁湾遭遇袭击，另一艘袭击并击沉了一艘英国船只。
Unmanned Houthi submarines pose new threat to US warships in Red Sea
The U.S. conducted what it calledself-defense strikes on five targets in the Houthi-controlled area of Yemenafter the Houthis employed an unmanned submarine for the first time since attacks in the Red Sea and Gulf of Aden began, the Pentagon said.
The submarine, an unmanned underwater vessel, or UUV, shows advancing Houthi capability and a shifting strategy, ABC News national security and defense analyst Mick Mulroy, a former Pentagon official and CIA agent, said.
"Unmanned surface and subsurface vessels are likely more difficult to detect and destroy than aerial drones and anti-ship missiles. The Houthis are not likely capable of manufacturing these weapons on their own, so they are probably coming from Iran," Mulroy said.
In addition to the unmanned submarine hit Sunday, the U.S.military said it struck an unmanned vessel that moves on the surface, as well as anti-ship cruise missiles which have made up the bulk of U.S. targets in the Houthi arsenal.
The Houthis, which the U.S. designates a global terrorist group with Iran's backing, operate out of parts of Yemen they control after a cease-fire in the Yemeni civil war. The International Revolutionary Guard Corps (IRGC) Quds Force, an arm of the Iranian regime's military forces that coordinates operations outside Iran's borders, supports the Houthis and other armed groups with weapons and financing, the U.S. says.
"The Houthis and the IRGC are adjusting their strategy, apparently because they haven't been successful in striking a U.S. naval vessel," Mulroy said. The Houthis have targeted American ships to no avail, while the U.S. has been increasing defensive strikes since a separate militia group, also backed by Iran, struck the U.S. base in Jordan and killed three servicemembers.
"If one or more of these weapons get through and kill U.S. sailors, Iran should expect to be held directly responsible," said Mulroy.
The unmanned weapons systems are an acute threat, Mulroy said, since they could "overwhelm the ship's defenses" by attacking from multiple dimensions, a so-called "swarm attack."
The U.S. Coast Guard said it intercepted a cache of weapons aboard a ship heading from Iran to Houthi-controlled Yemen on Jan. 15. Among military equipment intercepted were components for the unmanned vessels, the U.S. said – the sort of vessels hit in two of Sunday's U.S. strikes.
As a part of U.S. preemptive offensives to Houthi aggression, a U.S. official told ABC News the U.S. conducted a cyberattack against an Iranian spy vessel, the MV Behshad, which has cruised the Red Sea and passed targeting information to the Houthis. The cyberattack was a part of the U.S. promised multi-tiered response in the days after the January 28 militia attack in Jordan.
The Houthis on Monday said they conducted five strikes in the past 24 hours. Two targeted American ships in the Gulf of Aden and another targeted and sunk a British ship, the Houthis said in a statement.
