As tensions continue to rise between the United States and the Islamic Republic of Iran, and the risk of armed confrontation between the two powers continues to rise as the former reportedly contemplates strikes on the latter’s nuclear sites, while Tehran for its part threatens to close the Strait of Hormuz to international shipping - both illegal and highly provocative actions which could spark a major regional war dwarfing recent conflicts in Iraq, Syria and Yemen - an analysis of the means both powers have to wage a potential war becomes increasingly relevant. While Iran is militarily by far the weakest of the United States’ four ‘great power adversaries’ - the size and sophistication of its armed forces surpassed considerably by China, North Korea and Russia - it military has nevertheless prepared extensively for several decades for a potential conflict with the Untied States. Alongside sizeable investments in ballistic missiles, air defence and special operations force, the Iranian military has also invested heavily in strengthening its anti ship capabilities. With the waters of the Persian Gulf expected to be a key focal point in any conflict with the United States, and considering the central place of the U.S. Navy’s carrier strike groups to any potential attack plan against Iran, the strength of Iranian naval warfare capabilities remains a key and decisive factor not only in determining the outcome of a potential conflict - but also in deterring the U.S. from initiating such action. At face value Iran’s surface navy appears meagre in its capabilities to say the least, dwarfed by the might of even a single American carrier strike group - and in the event of war several such strike groups, most likely three or more, fully equipped with fighter jets are expected to be operating near Iranian shores. While the lack of carriers, a power projection asset, are hardly a hindrance should Iran be fighting a defensive war near or in its own waters within range of its airbases, the country lacks any destroyers and fields just four frigates and three corvettes. These warships are all either dated pre Vietnam War era designs or indigenous platforms of questionable quality - hardly considered a challenge for the American surface fleet. Iran’s main strengths at sea however come not from its large surface warships as in the case of the United States, but rather from asymmetric warfare capabilities designed specifically to counter the U.S. Navy and those of its allies on the country’s own terms. One of Iran’s primary assets are its vast arsenal of anti ship cruise missiles, which launched from the country’s combat aircraft such as the F-4D/E Phantom, Saqeh and Su-22 can skim the surface of the gulf’s waters to strike American warships at long ranges. Iranian Phantoms are considerably faster and fly at far higher altitudes than any fighters currently deployed by American carriers, and their indigenously manufactured Nasr and Qader cruise missiles, closely based on the Chinese C-704 and C-802 and developed with assistance from Beijing, can be deployed with state of the art anti jamming capabilities which combined with their low approach vectors make them extremely difficult to intercept. With these missiles expected to be launched in their hundreds, the threat posed to American carrier groups by these assets is great indeed. Iran fields a number of less prolific cruise missile designs which serve in complementary roles to the Nasr and Qadar, and according to a number of reports the country has sought to acquire the Russian Kh-31 - a game changing asset with a range approaching 200km, depending on the variant, and impacting at three and a half times the speed of sound. The kinetic energy of this missile’s impact alone is enough to disable almost any warship, while its speed eliminates the possibility of interception by any existing air defence systems. Complementing the capabilities of its missile equipped air wings, Iran’s submarine fleet is also potentially highly lethal against U.S. attacks. Comprised entirely of extremely silent diesel attack vessels, which have performed extremely well against larger but noisier American nuclear submarines, destroyers and carriers during wargames, these vessels are a key tool of Iran’s anti access area denial strategy at sea and pose a lethal threat to enemy warships. Alongside four Russian Kilo Class submarines, named ‘Black Hole’ by NATO for their extreme silence and carrying lethal Kalibr cruise missiles capable of posing a serious threat to American surface ships, Iran also operates a large arsenal of North Korean designed vessels and indigenous derivatives of these Korean ships. While deployment of the Sang-O Class, one of North Korea’s post prolific and quietest designs, remains unconfirmed - Iran does deploy the older Yugo Class, the Ghadir Class - a derivative of the Korean Yono, alongside the fully indigenous Nahang and Fateh Classes. Much like the Korean and Russian designs, these platforms prioritise silence - and while not as numerous or as sophisticated as the Russian or Korean fleets they remain a valuable and potentially lethal asset against U.S. carrier strike groups. Alongside attacks from above and below sea, Iran is threatening to target the U.S. Navy with surface vessels of its own - not with large warships but rather with small, fast and lightly armed speed boats, some remotely manned, designed to swarm enemy warships in large numbers. Referred to as a ‘guerrilla army at sea,’ these boats can carry an assortment of rockets and torpedos - often lethal modern designs - on near suicidal attack missions. While highly vulnerable to attacks from mini guns and other rapid fire weapons systems, with American carrier groups designed overwhelmingly for operations against either land based targets or larger enemy vessels at sea the vast majority of their armaments remain poorly suited to countering this threat. Though likely to take heavily losses, the speedboats can fast close in to their targets before unleashing salvoes capable of crippling large destroyer and possibly even carrier warships. While Iran formerly demonstrated a high level of proficiency in these tactics during the Iran-Iraq War in the 1980s, the development of new technologies including remote sailing, new rocket systems and a considerably larger fleet make speedboat attacks today considerably more dangerous. The U.S. Navy’s reported gross lack of training against such low end and highly unconventional threats further exacerbates their situation. Deploying such swarms, numbering several hundred boats both manned and unmanned, remains a major asymmetric threat to the might of America’s carrier strike groups. Other potentially lethal assets Iran may deploy include stealth drones equipped with anti ship munitions, anti ship ballistic missiles and cover from its air superiority fighter fleet and air defences. While Iran has already deployed advanced stealth aircraft based on the captured U.S. RQ-170, reportedly reverse engineered with Chinese assistance, and developed attack variants of these drones, equipping them for an anti ship role with advanced cruise missiles could well prove a highly lethal combination. Cheaper non stealth drones have reportedly already been equipped with Nasr cruise missiles as of 2015 to increase the volume of missile attacks and more effectively overwhelm a carrier strike group’s defences. Iran’s ballistic missile arsenal too could potentially be modified for an anti shipping role - and though this remains pure speculation, given its usefulness as an asset and the country’s heavy investment in ballistic assets this remains a considerable possibility. China’s armed forces, themselves having heavily modified ballistic missiles for ‘carrier killer’ roles, could again be key to providing assistance for such a program. Iranian operations against U.S. carrier strike groups are also likely to enjoy the support of air superiority fighters and, if operating near the country’s coasts ground based air defences. These include highly capable platforms such as the F-14 Tomcat, able to engage U.S. fighters well beyond retaliation range&nbsp;using the superior range of its lethal Fakour 90&nbsp;air to air missiles, and long range anti aircraft missile platforms such as the S-300 and Bavar-373 - all of which would seriously complication U.S. plans to deploy air cover in support of its naval assets. Even Iran's artillery, with the country currently fielding the world's longest ranged howitzer in the world - the 60km range North Korean Koksan 170mm gun&nbsp;which shoots projectiles invulnerable to interception across ranges longer than many of the country's cruise missiles, could well play a key role should U.S. warships approach too near the country's coasts. Iran’s combination of assets could well prove lethal enough to cause unacceptable losses to the United States Navy, and may be a key asset influencing Washington to avoid taking military action. A white shark may be the mightiest animal in the sea, but in a tank of Piranhas she will surely perish. Though the blue water primacy of the United States is unmatched, with the possible exception of the Pacific theatre,&nbsp;when fighting in Iran’s own waters, the piranha tank, there remains a considerable chance that it may not prevail.&nbsp;Iran by this logic plans to tear the United States Navy’s carrier strike groups using a combination of much smaller vessels including speed boats, drones, submarines and cruise missiles operating defensively on its own well prepared ground.