Yossi Alpher is an independent security analyst. He is the former director of the Jaffee Center for Strategic Studies at Tel Aviv University, a former senior official with the Mossad, and a former IDF intelligence officer. Views and positions expressed here are those of the writer, and do not necessarily represent APN's views and policy positions.

Q. On Saturday, the Houthi regime in Yemen openly declared a blockade of all Israeli and Israel-related shipping through the nearby Bab al-Mandab Straits. This, after harassing Israeli-owned shipping and firing missiles and drones at Israel since the Gaza War started on October 7. What’s the significance?

A. This is the first strategic development anywhere in the Middle East since the Gaza War began that threatens to expand the conflict well beyond Israel’s boundaries. The Houthis have even, presumably unintentionally, struck at non-Israel-related shipping. This means that there is now a potential threat to some 8.8 million barrels a day of oil shipped through Bab al-Mandab, which is one of the world’s crucial maritime chokepoints.

Attempts to block Israel-related shipping in the Red Sea-Indian Ocean region have been a feature of every major Israel-Arab war. It was only after the 1973 Yom Kippur War that Egypt unconditionally opened the Suez Canal and Red Sea navigation to Israeli shipping.

For the moment, Israel’s Zim shipping company has announced that it is rerouting its ships via Africa’s Cape of Good Hope--delaying goods by weeks. To the extent that non-Israeli shipping is endangered and maritime insurance rates go up, Egypt’s Suez Canal could be radically affected, with heavy economic costs for the beleaguered Egyptian economy. In other words, both Israel and Egypt have good reason and ample precedent to make sure that a Houthi shipping blockade is short-lived.

Thus far, with the possible exception of a mysterious arms depot explosion in Sanaa a week or so ago, Israel’s response to Houthi aggression in this war has been confined to intercepting incoming missiles and drones. An American naval presence in the southern Red Sea has countered the Houthis there.

But an Israel-Yemen conflict may only be commencing. After all, unlike Hezbollah to Israel’s north which is an active player in Lebanese politics, the Houthis are accountable to no one else in Yemen. For eight years they demonstrated considerable skill--backed by Iranian weapons and training--in fighting Saudi Arabia, inflicting huge losses with drone and missile strikes on Saudi (and UAE) energy installations. And they are far enough away from Israel, more than 1500 kms., as to render retaliation against them a logistical challenge. They field local versions of Iranian missiles and drones capable of striking as far as 2,400 km. away, meaning well inside Israel.

As Iranian analyst Nasser Imani noted recently, “We think Houthis in Yemen will become more of a threat to Israel in the long run than Hamas or even Hezbollah. Iran considers them a major player and part of the collective strategy of the resistance axis”. The Iran-led Resistance Axis, a primarily Shiite anti-Israel and anti-US alliance, comprises Hezbollah, Hamas, Syria, and various militias in Iraq and Syria in addition to the Houthis of Yemen. Over the past two years, against the backdrop of the Russia-Ukraine war, Tehran’s ties with Moscow as well have reached strategic proportions, including arms supply, as Russia’s President Putin recently acknowledged.

Q. Israel and Yemen had ancient ties--Solomon and Sheba. Yemeni Jews have made prominent contributions to Israeli culture. But has Israel had contemporary ties with the Houthis? Military ties?

A. One of the ironies of the Houthi attacks on Israel is that two generations ago we were allies. The Houthis, more formally known as Ansar Allah or Supporters of Allah, are Zaidi Muslims. The Zaidis of northern Yemen are associated with Shi’ite Islam. A Zaidi monarch, Imam Badr, ruled Yemen back in the 1960s when the Yemeni military led a “republican” coup against him and invited Egypt’s nationalist leader, Gamal Abd al-Nasser, to send troops to support them. Nasser sent an expeditionary force of tens of thousands to Yemen, accompanied by Soviet-piloted combat aircraft.

Those were the days when Nasser’s nationalist incitement inspired anti-monarchical movements throughout the Arab world. Imam Badr appealed to the neighboring Sunni Saudi monarchy for help. Back then, Zaidi-Sunni tensions were not an issue. The Saudis, via veterans of Britain’s Special Air Service, appealed to Israel.

Israel had good reason to help the Yemeni Zaidis’ fight (1962-1967) against Nasser’s forces. Egypt was then Israel’s principal enemy. The two countries had fought in 1948 and 1956. Egypt blockaded Israeli shipping to the east by closing the Strait of Hormuz at the southern tip of the Sinai Peninsula. Tensions between Egypt and Israel were high.

Israel also possessed stocks of Soviet weaponry taken as booty from the Egyptians in the 1956 Suez War. Arming the Zaidis against the Egyptians (with the latter’s own weaponry!) would strike an indirect blow against Nasser and pin down some of his forces far from home, in the mountainous north of Yemen. It would also, hopefully, ensure that a moderate Yemeni regime would not interfere with Israeli shipping to Asia via Bab al-Mandab.

Accordingly, over a period of months and years beginning in 1964, a single Israel Air Force B-377 Stratocruiser made 14 extraordinarily long (14-hour) flights south from Eilat in southern Israel, the length of the Red Sea to Yemen where surplus arms were parachuted under cover of darkness to the Zaidis high in their 12,000-foot-high mountain redoubt. The Stratocruiser then returned north to Eilat, refueling en route from barrels carried in the belly of the plane.

An undercover Israeli agent was on the ground in Yemen for the start of the operation. The Zaidis never knew the source of the weaponry, the identity of the agent or the mysterious aircraft. A handful of Saudis, and possibly Imam Badr, did know.

(Full disclosure: As a young first lieutenant in IDF Intelligence in Tel Aviv, I was dispatched to an ordnance base to make sure any Hebrew markings were erased from the Yemen-bound weapons and ammunition prior to a mission.)

Operation Rotev (gravy) succeeded. The British, anxious to unofficially protect their assets east of Suez (they would withdraw officially from Aden, Oman and elsewhere in 1971), played a major role, too. Imam Badr’s forces fought the Egyptian-aided Republican rebels to a standstill and a compromise settlement. The Saudis, via financial aid to the SAS, unknowingly paid the ‘gravy bill’. When the countdown to the Six-Day War began in late May 1967, some 30,000 Egyptian troops were pinned down in Yemen and unable to reinforce Egypt’s Sinai front--a net advantage of strategic proportions for Israel.

Fast forward to 2015, the height of the ‘Arab Spring’. Imam Badr is long gone. The Zaidis have rediscovered their Shiite roots. They are now known as the Houthis, after the northern Yemeni clan that leads them. Amidst heavy unrest in Yemen, their attempt some ten years ago to conquer all of Yemen brought Saudi Arabia and the United Arab Emirates in on the side of Sunni Yemenis and brought Iran in on the side of the Zaidis, their fellow Shiites. Under Iranian tutelage, the Houthis began spouting anti-Israel and anti-Semitic slogans, e.g. their trademark “God is great, death to America, death to Israel, a curse upon the Jews, victory to Islam.”

Considering the circumstances, the last Yemeni Jews left Houthi territory a few years ago.

Note that southern Yemen is not occupied by the Houthis. It is under a patchwork of Saudi, UAE and even al-Qaeda influence. If we are harking back to Yemen’s recent past, from 1967 until the fall of the Soviet Union in 1990, southern Yemen was the People’s Democratic Republic of Yemen (PDRY), the Arab world’s only Marxist-communist country.

Q. How does Saudi Arabia enter the current picture of the Houthi attacks against Israel and Israeli shipping?

A. When Israel was attacked by Hamas on October 7, Israel and Saudi Arabia appeared to be making progress toward normalization of their relations. Saudi Arabia had fought the Houthis, clumsily and ineffectively, for the past nine years; a tenuous ceasefire took hold a year ago. Now, were Israel to become more directly involved in fighting Yemen, the violence could easily spill over onto Saudi territory and jeopardize nascent Israeli-Saudi relations, which have been on hold since the Gaza War began.

Think of a triangular relationship: Israel, Saudi Arabia, Yemen. One of Hamas’s aims in starting the war on October 7 was to scuttle Israel’s normalization with Saudi Arabia by whipping up Islamist fervor. One of Iran’s aims in egging on the Houthis to attack Israel and Israel-related shipping is also to hurt Israeli-Saudi normalization.

Q. All of this seems very far away from Israel’s war in Gaza . . .

A. One of Israel’s aims since the outbreak of war on October 7 has been to deter Hamas’s Axis of Resistance allies from joining the fray, which is almost certainly what Hamas leader Yihya Sinwar intended. The US shares this goal of preventing regional escalation; this explains the presence of American aircraft carriers in the eastern Mediterranean (explicitly deterring Hezbollah in southern Lebanon) and the Persian Gulf region (implicitly deterring Iran).

Accordingly, both Israel and the United States presumably seek to avoid escalation in the southern reaches of the Red Sea. The Houthis declare they will attack Israel and Israel-related shipping as long as Israel fights Hamas in Gaza. So one Israeli option could be simply to contain Houthi attacks, without attacking the Yemeni mainland, until the war can be declared ended (and then hope that the Houthis indeed cease their attacks).

That is what Israel currently is doing. But unless Houthi attacks end soon, the economic cost of the Houthi threat to shipping and its weakening effect on Israeli deterrence could oblige Israel to weigh the option of retaliating. This in turn could catalyze a radical expansion and escalation in the Gaza war--far away from Gaza. And that could further jeopardize already strained US-Israel relations.

This explains recent reports that the United States is organizing an international force to patrol the southern Red Sea and keep Bab al-Mandab open to all shipping.