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Iran Update, September 15, 2026

ISW · Institute for the Study of War ·

Executive Summary

The Houthis are expanding their strike campaign into Saudi Arabia, likely to pressure Riyadh to end military operations in Yemen and accept Houthi demands. This expansion may be linked to Saudi efforts to reroute oil exports through the Strait of Hormuz, facilitated by recent US successes in ensuring freedom of navigation. Iranian hardliners continue to dominate decision-making, willing to risk conflict to achieve objectives like controlling the Strait of Hormuz.

Why It Matters

This document provides critical insights into escalating regional conflicts, Iranian strategic objectives, and the complex interplay of military actions, energy security, and diplomatic efforts in the Middle East, directly impacting defense and geopolitical stability.

Key Takeaways

  • The Houthis are expanding their strike campaign into Saudi Arabia, aiming to compel Riyadh to cease military operations in Yemen and accept Houthi demands.
    Source evidence · PDF page 2
    The Houthis are likely expanding their strike campaign into Saudi Arabia to erode Saudi support for military operations in Yemen and compel Riyadh to accept Houthi demands.
  • Saudi Arabia's increased oil exports through the Strait of Hormuz, supported by US efforts to ensure freedom of navigation, limit Houthi leverage over Saudi oil routes.
    Source evidence · PDF page 3
    Saudi Arabia’s ability to increase oil exports through the Strait of Hormuz may reflect recent US successes in efforts to restore freedom of navigation to the strait.
  • Iranian hardliners remain the primary decision-makers, demonstrating a willingness to risk military conflict with the US to achieve key objectives, including control over the Strait of Hormuz.
    Source evidence · PDF page 4
    Iranian officials’ accounts confirm that hardliners remain the principal decision-makers within the regime. These actors have demonstrated their willingness to risk military conflict with the United States in order to achieve key Iranian objectives, such as retaining Iranian control over the strait.

Strategic Relevance

The report highlights the escalating Houthi threat to Saudi Arabian infrastructure and shipping, the strategic importance of the Strait of Hormuz for global energy security, and the persistent influence of hardline factions within Iran's decision-making, all of which have significant implications for regional stability and international maritime security.

Source Website View PDF

Key Entities

HouthisSaudi ArabiaIranUnited StatesStrait of HormuzYemenInstitute for the Study of War (ISW)Critical Threats Project (CTP)IRGCMojtaba KhameneiHossein TaebMasoud Pezeshkian

Best For

Policy MakersIntelligence AnalystsMiddle East SpecialistsEnergy Security AnalystsMilitary Strategists

Related Themes

Regional ConflictsMaritime SecurityEnergy GeopoliticsIranian Foreign PolicyProxy WarfareUS Middle East Policy

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