US-Iran war bill explodes to $38B—while Houthis push Saudi into a proxy crisis

The Pentagon has spent roughly $38 billion in the first few months of the US war with Iran, according to reporting cited by the Wall Street Journal, while the Congressional Budget Office (CBO) estimates the direct fiscal cost has already reached about $38 billion over the first five months. A separate CBO-linked analysis projects the war’s monthly cost could rise by about $3 billion going forward. Bloomberg adds that President Donald Trump’s decision to go to war has also lifted inflation pressure, with a new congressional study estimating an increase of around 0.5 percentage points by early next year. Taken together, the articles frame a rapid escalation in both defense outlays and macroeconomic spillovers, with the US government absorbing the bill while inflation risks feed back into domestic politics. Strategically, the war’s regional second-order effects are now colliding with Saudi Arabia’s security calculus. One article argues the US-Iran conflict has reached a crisis point for Saudi Arabia and for Crown Prince Mohammed bin Salman, implying Riyadh is facing mounting pressure from Iran-linked proxy dynamics even as it tries to manage escalation. Another piece highlights Tehran’s denials that it “controls the Houthis,” but asserts senior IRGC commanders in Tehran ordered the 8 September attacks on Saudi Arabia and coordinated with IRGC personnel on the ground in Yemen. A further report describes a “Mecca Alliance” warning Iran over Houthi attacks, signaling a coalition-building effort that could harden deterrence and complicate any Iranian effort to keep proxy conflict deniable. On markets, the most immediate transmission mechanism is energy and inflation. Article coverage notes that stubborn August inflation is likely to keep consumers feeling financial pain as Middle East tensions flare, driving up gasoline and other energy costs; this aligns with the CBO’s inflation estimate tied to the war. The Saudi proxy pressure also raises the risk premium on regional supply routes and could lift expectations for higher fuel and shipping insurance costs, even if the articles do not provide specific price prints. In the US, the $38B-to-$3B-per-month trajectory implies sustained fiscal drag, which can influence Treasury issuance expectations and risk appetite across defense, industrials, and energy-linked equities. What to watch next is whether the proxy front widens beyond Saudi Arabia and whether Washington and Tehran signal any off-ramps. Key indicators include additional Houthi strike claims or Saudi interception statistics, any further IRGC-linked attribution from regional or Western sources, and whether the “Mecca Alliance” expands membership or issues operational guidance. On the US side, monitor CBO updates, Pentagon supplemental requests, and inflation prints for confirmation of the projected ~0.5pp effect by early next year. Trigger points for escalation would be sustained attacks on critical Saudi infrastructure or a visible shift from deniable proxy activity to more direct cross-border engagement, while de-escalation would likely hinge on credible channels that reduce the incentive for Tehran to escalate through Yemen and for Riyadh to seek broader coalition action.

Geopolitical Implications

• 01

  Sustained US fiscal burden may shape Washington’s willingness to sustain high-tempo operations versus pursuing negotiated off-ramps.

• 02

  Proxy conflict in Yemen is becoming a direct Saudi security problem, increasing the likelihood of regional coalition action against Iran’s influence networks.

• 03

  Attribution of attacks to IRGC commanders in Tehran raises the risk of retaliatory cycles and miscalculation across air and maritime domains.

Key Signals

• —Next CBO and Pentagon cost updates (monthly run-rate) and any supplemental funding requests
• —Saudi interception rates and reported target types (energy infrastructure vs. military sites)
• —Public messaging and membership changes around the ‘Mecca Alliance’
• —US inflation and gasoline price indicators for confirmation of the projected inflation impulse