The dispute arose on 27 December 2011, when Iranian Vice President Mohammad-Reza Rahimi threatened to close the Strait of Hormuz.

The battle, dubbed Operation Praying Mantis by the U.S. side, was launched in retaliation for the mining of USS Samuel B. Roberts on 14 April by Iran.

Instead, Iran aims to "exploit enemy vulnerabilities through the used of 'swarming' tactics by well-armed small boats and fast-attack craft, to mount surprise attacks at unexpected times and places" which will "ultimately destroy technologically superior enemy forces," writes Iranian military expert Fariborz Haghshenass in a 2008 study based on published doctrines of the Islamic Revolutionary Guard Corps (IRGC).

The Monitor also makes reference to Millennium Challenge 2002, a major war game exercise conducted by the United States armed forces in mid-2002, in which Red forces, commanded by retired Marine Corps Lt. General Paul K. Van Riper, used old methods to evade Blue's sophisticated electronic surveillance network, and a significant portion of Blue's navy was "sunk".

[11] Also on that date, the U.S. aircraft carrier USS John C. Stennis concluded a four-day port visit to Jebel Ali, United Arab Emirates, and returned to the North Arabian Sea in support of coalition ground operations in Afghanistan via the Strait of Hormuz.

[17] The U.S. Navy spokesman Commander Bill Speaks responded that deployment of U.S. military assets would continue as has been the custom stating: "The U.S. Navy operates under international maritime conventions to maintain a constant state of high vigilance in order to ensure the continued, safe flow of maritime traffic in waterways critical to global commerce.

[25] The US had previously announced its intention to warn Iran that closing the Strait of Hormuz is a "red line" that would provoke an American response.

Defense Secretary Leon E. Panetta told troops in Texas that the United States would not tolerate Iran's closing of the strait.

A senior member of Iran's parliament said that the Islamic Republic would close the entry point to the Gulf if new sanctions blocked its oil exports.

[34] "If any disruption happens regarding the sale of Iranian oil, the Strait of Hormuz will definitely be closed," Mohammad Kossari, deputy head of parliament's Foreign Affairs and National Security Committee, told the semi-official Fars News Agency.

[35][36] In addition to combat air support for coalition forces in Afghanistan, Carrier Strike Group Nine maintained flights operations some 30 nautical miles (56 km; 35 mi) off the coast of Iran.

[40][41] In July 2012, Iranian General Hasan Firouzabadi announced Iran's plans to block the Strait of Hormuz if the country's interests are seriously threatened.

[40] Pressure on prices reflect a combination of uncertainty driven further by China's recent response – reducing oil January 2012 purchases from Iran by 50% compared to those made in 2011.

[49] The closure of the Strait of Hormuz would inflate oil prices, not only in the west but in Asian countries such as Japan, India, and South Korea.

[50] A number of countries dispatched warships to the Persian Gulf and Arabian Sea in an effort to ward off any Iranian closure of the Hormuz Strait.