No one is taking a closer interest in the political fall-out from the devastating explosion at the port of Beirut that killed more than 200 people and injured thousands of others than Iran. For nearly 40 years Tehran has invested heavily, both politically and financially, in the Mediterranean state as part of its commitment to exporting the principles of its <a href="https://www.thenational.ae/opinion/comment/iran-s-revolution-has-failed-its-women-1.982880" target="_blank">1979 Iranian Revolution</a>. As one of the few countries in the Arab world where Shiite Muslims form the majority of the population, Lebanon, and especially the Shiite heartlands in the south, has been ripe for exploitation by Iran, an opportunity that became even more inviting after large swathes of the region were laid waste by Israel’s 1982 invasion of Lebanon. But while Iran’s original claim, when it helped to create the Hezbollah militia in the early 80s, was to help Lebanon bring the Israeli occupation to an end, the organisation’s influence in the country's political arena has grown immeasurably since then – to the extent that Hezbollah has become one of the country’s most influential power-brokers. Despite the fact that Hezbollah is widely condemned in the West as being little more than a terrorist organisation, which has resulted in countries like Britain finally <a href="https://www.thenational.ae/opinion/comment/the-beirut-tragedy-must-push-europe-even-further-to-tackle-hezbollah-head-on-1.1060707" target="_blank">ending the distinction</a> between the organisation's political and military wings, it continues to wield enormous power and influence in Beirut. Hezbollah's pre-eminent position in Lebanese politics is enshrined in the 2006 memorandum of understanding it signed with the country's Christian head of state, President Michel Aoun, as part of his attempts to consolidate his position. In return for recognising the rights of Lebanon's Christian minority, Hezbollah was accepted into the political mainstream, a move that has had <a href="https://www.thenational.ae/opinion/comment/beirut-s-suffering-is-a-direct-result-of-a-failed-political-system-in-need-of-overhaul-1.1062148" target="_blank">disastrous consequences</a> for the rest of the nation. Today, such is the power that Hezbollah exercises that hardly any decision of consequence is taken without referral to the organisation’s leadership. Moreover, no move made by Hezbollah is undertaken without prior consultation with Tehran, so that much of Lebanon has become little more than a client state of Iran. This takeover is central to Tehran's strategic goals. It provides the regime with an active front line in southern Lebanon in its long-standing <a href="https://www.thenational.ae/world/mena/hezbollah-says-all-out-war-with-israel-unlikely-in-coming-months-1.1055059" target="_blank">confrontation with Israel</a>, with its paramilitary militia organisation, the Islamic Revolutionary Guard Corps, making regular arms shipments – including medium-range missiles – to Hezbollah positions there. It also provides Iran with a base from which to spread its malign influence throughout the region, most recently in neighbouring Syria, where Hezbollah fighters have been involved in <a href="https://www.thenational.ae/opinion/comment/for-many-syrians-qassem-suleimani-is-the-man-who-brutalised-millions-just-to-save-bashar-al-assad-1.961659" target="_blank">the campaign to save</a> the brutal dictatorship of President Bashar Al Assad – and sustained serious casualties as a consequence. Now, in the wake of the Beirut port atrocity, there are mounting concerns in Tehran that Iran's long-standing ability to exercise its influence over Lebanon might be in doubt, thereby depriving it of one of the fundamental pillars of its attempts to <a href="https://www.thenational.ae/opinion/comment/arab-states-reduced-to-proxy-playing-fields-for-other-regional-powers-will-usher-in-period-of-unrest-1.961501" target="_blank">consolidate its position</a> in the Arab world. Although the investigation into the devastating explosion is still ongoing, there is a growing recognition among Lebanese protesters that Hezbollah is ultimately responsible for the blast, because the militia has effectively assumed control of the port, which it has used – among other activities – as a convenient route for shipping arms to southern Lebanon. A report published by US think tank <em>Atlantic Council </em>shortly after the blast concluded that, while the 2,750 tonnes of ammonium nitrate that caused the explosion may not have belonged specifically to Hezbollah, the organisation knew of its existence, and therefore bears some responsibility for the explosions. Hezbollah’s extreme sensitivity over any suggestion that it shares the blame for the tragedy can be seen in vociferous denials of wrongdoing that have emanated from the group's leadership. In an interview with the movement’s Al Manar television station, Hassan Nasrallah, the organisation's leader, denied allegations that it was responsible for the blasts – despite being a key member of the coalition government when it occurred. “If you want to start a battle against the resistance over this incident, you will get no results,” Nasrallah declared. “The resistance, with its strength and patriotism, is greater and bigger and stronger than to be hit by those liars who want to push and provoke for civil war.” In addition, Hezbollah has been pumping out fake news on the internet, with one blog, Sada Al Fikr, claiming that Britain had dispatched a Royal Navy aircraft carrier to the eastern Mediterranean in preparation for an invasion of Lebanon - even though neither of Britain’s new 65,000-tonne, Queen Elizabeth-class aircraft carriers are operational. Hezbollah’s attempts to absolve itself of any blame for the explosion, though, are making little headway in Lebanon, where a number of prominent figures, such as Bahaa Hariri, eldest son of the country’s murdered former prime minister Rafik Hariri, is openly demanding the group's removal from the political system. Moreover, the pressure on Hezbollah is expected to increase further next week when the <a href="https://www.thenational.ae/world/mena/special-tribunal-for-lebanon-delays-verdict-after-beirut-blast-1.1059543" target="_blank">special tribunal</a> set up by the UN to try the four Hezbollah terrorists accused of assassinating Hariri in a car bomb attack in 2005 issues its judgement. A guilty verdict confirming Hezbollah’s involvement in the murder of a democratically elected prime minister would make its future participation in Lebanon's politics completely untenable, and undermine Iran’s unwelcome involvement in the country’s affairs. <em>Con Coughlin is the Telegraph’s defence and foreign affairs editor</em>