There are a few new numbers out on munitions availability  on either side of the conflict.

The Washington Post says (archived) that the U.S. has fired some 850 Tomahawk cruise missiles onto Iran. The total available stock of Tomahawks is somewhere between 3,000 and 4,000.

But the limit for the use of these long reach weapons is elsewhere. The missiles are usually fired from U.S. Navy vessels. They have limited loads of up to 72 Tomahawks each. When those are expended the vessels need to leave the scene to go to a friendly harbor for reloading. (Reloading large missiles at sea has been tested by is still in its infancy.)

The 16 or so destroyers and submarines the U.S. has around the Gulf are by now mostly ‘Winchester’, i.e. out of Tomahawk missiles to fire. But they can no leave the scene yet as their air-defense capabilities are still needed to take on Iranian missiles.

Air-defense missiles are also lacking. As the British Royal United Service Institute (RUSI) reported three days ago:

[O]ver a dozen munition types have been expended by the coalition at a rate that appears to be unsustainable. Already, Rheinmetall CEO Armin Papperger noted on 19 March that global stockpiles are ‘empty or nearly empty’ and that if the war continues another month ‘we nearly have no missiles available’.
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Given that Iran has damaged at least a dozen US and allied radars and satellite terminals, the efficiency of interception decreases; using 10 or 11 interceptors for one missile or 8 patriot missiles for one drone becomes unsustainable.
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[T]he US military is approximately a month, or less, away from running out of ATACMS/PrSM ground-attack missiles and THAAD interceptors. Israel is in an even more precarious spot, with its Arrow interceptor missiles likely to be completely expended by the end of March. While the war could proceed with other munitions, this implies accepting greater risk for aircraft and tolerating more missile and drone ‘leakers’ damaging forces and infrastructure.

RUSI provides some tables and background on the industry difficulties to replenish the stockpiles.

On the other side of the equation is the damage the USraeli campaign has done to Iran. Over 10,000 ‘targets’ have been hit but the main aim of defeating Iran’s ballistic missile capabilities is, despite President Trump’s claims, still far from being reached:

The United States can only determine with certainty that it has destroyed about a third of Iran’s vast missile arsenal as the U.S. and Israeli war on the country nears its one-month mark, according to five people familiar with the U.S. intelligence.

The status of around another third is less clear but bombings likely damaged, destroyed or ‌buried those missiles in underground tunnels and bunkers, four of the sources said. The sources spoke on condition of anonymity given the sensitive nature of the information.

One of the sources said the intelligence was similar for ‌Iran’s drone capability, saying there was some degree of certainty about a third having been destroyed.
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The intelligence stands in contrast to President Donald Trump’s public remarks on Thursday that Iran had “very few rockets left”.

If one compares the numbers of attacks per day the USraeli side has a large advantage. It is currently flying some 300 missions per day dropping bombs and missile on Iranian targets. Iran is firing about 30 to 40 missiles per day. The question though is the quality of such strikes. The USraeli side has from the very first day on targeted civilian infrastructure like schools and medical clinics while the Iranian side has attacked military and military-industrial installations.

Today the USraeli strikes hit Iranian steel plants in Khuzestan and Mobarakeh near Isfahan. Iran announced that it will hit back at similar installations in Israel and the Arab Gulf states. It is this ability to retaliate that is protecting Iran from the potentially most devastating attacks.

Iran’s position is giving it escalation advantage.

The editors of the Iran-hating Economist acknowledge this when they urge the U.S. (archived) to accept that it has no way to win this war:

In short, for all the power and sophistication of the military onslaught from America and Israel, Iran feels it has the upper hand over Mr Trump. It has shown that it is more capable than America of both inflicting pain and withstanding it. Mr Trump launched his war, unforgivably, without offering a strategic rationale for it. Despite operational successes and his nonsensical claim of having already changed the regime in Tehran, he has yet to win any substantive gains from the fighting. As the political costs mount, Mr Trump will come under growing pressure.
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Mr Trump must agree to a full ceasefire, and compel Israel to abide by it. Talks on reopening the strait and steering Iran away from its nuclear programme will be bitterly difficult. And any eventual deal will be worse than what could have been struck before the war began, because Mr Trump has unwittingly strengthened the hand of hardliners and made clear the leverage they have over the strait. The result is that for now, at least, the advantage lies with Iran.

Trump might of course chose the alternative and escalate the war. But the prospect of doing that are no better than the current position.

Meanwhile U.S. allies are suffering from the war the U.S. has started. Australia is in an especially bad position. While it is producing and exporting crude oil it is depending on imports of petroleum products from Asia. As these are no longer available it has to buy diesel and gas from other sources which are extraordinary expensive:

Transit times from the US Gulf Coast to Australia stretch to 55–60 days, with freight costs around $20/bbl, compared with typical Asia-Pacific routes that stood at $5–6/bbl before the crisis. The price dynamics of regional products briefly blurred that disadvantage: on March 18, delivered gasoline and diesel from Singapore and Houston converged at roughly $161/bbl. As of March 25, Singapore cargoes look more attractive again — around $153/bbl versus $164/bbl from Houston. But pricing is no longer the decisive factor. The issue has shifted to physical availability. With unsold cargoes in Asia increasingly rare, the US – despite longer routes and more expensive freight – might become the only reliable way out of this imports’ deadlock for Canberra.

Global crude oil supplies are still shrinking. U.S. gas and diesel prices are still increasing. One wonders how long it will take for Trump and the U.S. to prohibit all exports of petroleum products. That will be the moment when Australia will awake to the real value of its alliance with the U.S. of A.