Yemen’s War Reignites as Lebanon’s Army Completes Only Half a Job

This week

Issue No. 1 asked whether Lebanon’s army would enforce disarmament, not just announce it, and whether Gaza’s roadmap would survive contact with the ground. Both answers arrived, and both were the harder one. A third file broke open entirely: Yemen’s civil war, which this briefing had treated as a shipping-chokepoint story, is now also an open war for the country’s south.

This issue answers the two questions Issue No. 1 left open and adds a third file that has moved further and faster than either: heavy fighting broke out between the Houthis and Yemen’s internationally recognised government on 3 September, the sharpest escalation of the war in months, arriving just as the Southern Transitional Council’s formal collapse leaves the anti-Houthi side without the coalition structure it had a year ago.

Yemen

Heavy fighting between the Houthis and the PLC broke out on 3 September. The STC’s collapse in January removed the south’s political umbrella, but not its armed capacity — a combination that tends to make wars longer, not shorter.

1. Yemen: A War That Was Supposed to Be Winding Down

Heavy fighting between Houthi forces and the Presidential Leadership Council broke out on 3 September — the sharpest escalation reported in months. It followed a warning from the UN Special Envoy for Yemen in August that intensifying fighting carried a “more serious risk of return to large-scale conflict,” itself issued after Houthi strikes on Saudi Arabia’s Abha airport in July (House of Commons Library, 2026).

The PLC’s own coalition has grown less unified, not more, over the same period. In January, a PLC counter-offensive rapidly reversed the Southern Transitional Council’s territorial gains; STC leader Aidarus al-Zoubaidi was removed from the Presidential Council, charged with treason, and left for the UAE, and the STC announced its own dissolution. But the forces beneath that political structure did not disappear: the Support and Reinforcement Brigades, which fought alongside the former STC security forces, announced full combat readiness this month and called on the wider Southern Resistance to unite. A conflict that looked, in January, like it was consolidating into two sides now risks fragmenting into three or four just as the Houthi threat intensifies.

Sources: House of Commons Library, “Yemen in 2026: STC’s fall and intensifying Houthi conflict”; UN Special Envoy for Yemen briefing, August 2026.

Lebanon

The army finished disarming the south of the Litani river and calls it a genuine state monopoly on arms there. Hezbollah has rejected the government’s four-month timeline for everywhere else.

2. Lebanon: Half the Country Disarmed, Half Refusing

The Lebanese army announced that phase one of its “Homeland Shield Plan” is complete: all non-state weaponry between the Litani river and the Israeli border is now, in the army’s words, under an “effective and tangible” state monopoly, with the exception of positions Israel itself still occupies. On 5 September the government welcomed — but stopped short of fully endorsing — the army’s plan for the remaining phases, and granted the military at least four more months to extend the process nationwide (Al Jazeera, 2026).

Hezbollah’s answer was immediate rejection. The movement said it would not accept a four-month runway it characterised as serving Israel’s interests, restating its position that any disarmament follows an Israeli withdrawal, not precedes it. Issue No. 1’s judgement holds: an enforcement mechanism south of the Litani is real progress; a rejected timeline for the rest of the country is not.

Sources: Al Jazeera, “Lebanon’s army says phase one of disarming non-state groups in south complete,” January 2026 reporting cycle, updated September; Yahoo News/AFP, September 2026.

Gaza

Hamas has agreed to a detailed roadmap tying its disarmament to an Israeli withdrawal over roughly three years. Israel has not confirmed it accepts that roadmap.

3. Gaza: An Agreement With One Signature Missing

Hamas and other Palestinian factions have formally agreed to a document mapping their disarmament, with mediators from Egypt, Qatar, Türkiye and the United States finalising the text. Under its terms, Hamas transfers governing, civil and security authority to a technocratic body — the National Committee for the Administration of Gaza — with full disarmament tied to a roughly three-year Israeli withdrawal timeline; each stage depends on the other happening first (Chatham House; Principles for Peace; The Washington Institute, 2026).

Israel has not confirmed it accepts the roadmap. Hamas says it will not move on any part of the deal unless Israeli withdrawal obligations are met in parallel, and gaps over sequencing and oversight remain unresolved. Issue No. 1 called this ceasefire fragile and reversible until verification and withdrawal lines were agreed, not announced; five weeks on, they still have not been.

Sources: Chatham House, “By agreeing to disarm, Hamas is trying to call Israel’s bluff in Gaza,” August 2026; The Washington Institute, “Hamas Accepts the Gaza Roadmap,” 2026.

Iran & the Gulf

A vessel was struck near the Strait of Hormuz this week, a second contested chokepoint operating alongside Bab el-Mandeb at the same time.

4. Iran and the Gulf: Two Chokepoints, One Week

This briefing’s Daily Briefing covered the immediate incident on 14 September: a vessel was struck near the Strait of Hormuz even as Houthi forces completed their hold on Bab el-Mandeb further south. The two corridors carry a large share of the world’s oil and container traffic between them; having both contested in the same week is now this briefing’s working assumption for regional shipping risk, not an anomaly to note once and move past.

For decision-makers

Four judgements from the fortnight.

Briefing Points

• On Yemen: Treat the PLC coalition as more fragile than it was in August, not less — a formally dissolved STC with an armed, remobilising wing is a harder actor to negotiate with than an intact one.
• On Lebanon: The south-of-Litani result is real and should be credited as such. It is not evidence the next phase will go the same way; Hezbollah’s rejection is the more decisive fact for the next four months.
• On Gaza: An agreed document without Israeli confirmation is a draft, not a roadmap in force. Watch for Israel’s formal response before treating any disarmament timeline as real.
• On shipping: Plan for Hormuz and Bab el-Mandeb as simultaneous, ongoing risks. Sequential contingency planning for one chokepoint at a time is no longer the realistic scenario.

Bottom line

Every file this briefing is tracking moved partway and stopped. Lebanon disarmed a third of the country. Gaza has a document but not a signature. Yemen’s coalition fractured before its war even the one that mattered most.

Conclusion

Issue No. 1 asked where American leverage runs out. This issue’s answer is that it runs out at the point where an actor’s survival, not its preferences, is at stake: Hezbollah will trade a partial defeat in the south for refusing a timeline that ends its arsenal everywhere; Hamas will sign a document but not disarm ahead of an Israeli withdrawal it does not trust; and Yemen’s Houthis, facing a divided opponent, chose escalation over restraint. None of these actors called Washington’s bluff by refusing outright — they simply moved as far as their own survival allowed and stopped. That is the pattern this briefing will keep testing in Issue No. 3.