The conflict initiated under former President Donald Trump’s administration against Iran has had wide-ranging and lasting impacts on global security and military readiness, according to defence experts and security sources. The ongoing war, which has already cost tens of billions of pounds, has strained international relations, destabilized sensitive regions in the Middle East, and depleted crucial military stockpiles.

Since the conflict began, U.S. forces have launched strikes on more than 13,000 Iranian targets, with the Pentagon reporting 18 American service members killed and over 600 wounded. Meanwhile, Iranian authorities estimate more than 3,500 casualties on their side. The extensive military engagement has significantly drained U.S. missile inventories, prompting concerns about the country’s ability to maintain global defense postures and respond to other international crises.

Central to this depletion are the Patriot missile defense system and the more advanced Terminal High Altitude Area Defense (THAAD) system. American forces have reportedly expended nearly 1,430 Patriot interceptors out of an estimated pre-conflict stockpile of 2,330, alongside hundreds of THAAD interceptors from a limited pre-war total of roughly 360. Each Patriot interceptor costs approximately £3 million, underscoring the financial burden of replenishment. Experts warn it could take at least two years to restore missile stocks to levels considered adequate for global defense needs.

The conflict has also seen substantial use of Tomahawk cruise missiles, with estimates suggesting that about 1,000 of the 3,000 pre-war missiles have been fired. Officials have acknowledged that restarting production and rebuilding these inventories may take up to 2031, further complicating the United States’ ability to project power in multiple theaters simultaneously.

The strain on U.S. military resources occurs alongside rising tensions in other parts of the world. China’s stated objective to be prepared for a possible Taiwan invasion by 2027 adds urgency amid concerns about America’s capacity to aid Taiwan if conflict arises. A recent report from Tel Aviv’s Institute for National Security Studies warns of various potential Chinese strategies, including missile strikes, targeted special operations, or full-scale amphibious assaults.

Meanwhile, Iran’s Islamic Revolutionary Guard Corps has intensified collaboration with proxy groups across the Middle East and Africa, including cooperation between Shia and Sunni militant factions. Such alliances, including coordination with groups like al-Shabab in Somalia, signal an escalating and more complex threat environment. UK security sources have highlighted the growing risk posed by terror organizations such as Islamic State, which are exploiting the instability created by the Iran war to expand their reach and plot attacks, including against Europe.

The conflict’s strategic implications also extend to Ukraine, where Russian missile attacks on Kyiv have increased, underscoring the critical need for Patriot missile systems that are increasingly in short supply due to the Iran conflict.

Throughout, critics argue the war has lacked clear strategic objectives and has exacerbated geopolitical tensions. Some U.S. defense officials assert that additional funding—approximately £68 billion—is required to address critical shortfalls in military capabilities. Observers point to challenges posed by fragmented global alliances and intelligence sharing, noting reports that Russian intelligence may have aided Iranian forces by providing targeting information against U.S. bases in the Middle East.

The ramifications of the ongoing war in Iran underscore a broader shift in the global security landscape, raising questions about the sustainability of current U.S. military engagements and the ability of Western powers to respond effectively to emerging threats on multiple fronts.