As long-simmering tensions heat up between the United States and Iran in the Middle East, a look at the various countries or players involved, and what could happen:
The U.S. has tens of thousands of troops scattered across military bases in the Middle East. It recently sent the USS Abraham Lincoln aircraft carrier and strike group to the region, as well as B-52 bombers. That complements the warships of the 5th Fleet in Bahrain, the soldiers of U.S. Army Central in Kuwait, the drones and fighter jets stationed in the United Arab Emirates and the forward headquarters of the U.S. military's Central Command in Qatar. President Donald Trump has threatened Iran with attack if it first launches an assault on U.S. interests. However, Trump also has sought at times to soften his tone amid his maximum pressure campaign against Tehran, to go with additional sanctions that Washington has imposed after withdrawing from the 2015 nuclear deal that Iran reached with world powers. Analysts fear the chance of a miscalculation by either Iran or the U.S. amid the tensions. The U.S. also has developed cyberwarfare capabilities.
Although Israel has been silent amid the recent tensions, it has played a key role in getting the region to this point. Prime Minister Benjamin Netanyahu, who considers Iran to be his country's greatest enemy, welcomed Trump's withdrawal from the nuclear deal and encouraged renewed economic sanctions. Israeli officials have portrayed the standoff as a matter between Iran and the U.S. But if fighting breaks out, Israel could be targeted by Iran's regional proxies, such as Hezbollah in Lebanon or Islamic Jihad in Gaza. Israel has the Middle East's most powerful and advanced military, with F-15 and F-16 warplanes, as well as the next-generation F-35 fighter jet. It also has warships, submarines and long-range missiles. Israel has a missile-defense system capable of intercepting anything from long-range missiles to short-range rockets fired from Gaza or Lebanon. Israel is widely believed to have a nuclear arsenal, which it neither confirms nor denies. Israel has acknowledged carrying out scores of attacks on Iranian targets in neighboring Syria, sometimes drawing retaliation. Israel, which has conducted pre-emptive bombings of nuclear facilities in Iraq and Syria, has vowed to never allow Iran to obtain an atomic weapon. It also has developed cyberwarfare capabilities.
The Sunni rival to Shiite Iran, Saudi Arabia long has watched Tehran with suspicion since its 1979 Islamic Revolution. Relations have cooled and warmed in the last four decades. The U.S. push for the 2015 nuclear deal drew Saudi anger. Since the rise of King Salman and his assertive, 33-year-old son, Crown Prince Mohammed bin Salman, the kingdom has taken a far-more militant line. It launched the war in Yemen, targeting Iranian-allied Houthi rebels. Prince Mohammed also compared Iran's Supreme Leader Ayatollah Ali Khamenei to Nazi Germany's Adolf Hitler. "We won't wait for the battle to be in Saudi Arabia," the prince told the Saudi-owned broadcasting company MBC in 2017. "Instead, we will work so that the battle is for them in Iran, not in Saudi Arabia." A top Saudi diplomat said the kingdom does not want war but won't hesitate to defend itself against Iran. Saudi Arabia has a fleet of over 250 fighter jets capable of launching a strike on Iran.
UNITED ARAB EMIRATES
The seven sheikhdoms of the United Arab Emirates have long historical ties to Iran, but diplomatic relations between Abu Dhabi and Tehran have worsened in recent years. Analysts believe Abu Dhabi's powerful crown prince, Sheikh Mohammed bin Zayed Al Nahyan, largely runs day-to-day affairs and military strategy. In U.S. State Department cables released by WikiLeaks, Sheikh Mohammed painted a dire picture of Iran in multiple meetings. He told U.S. diplomats in 2009 he believed "'all hell will break loose' if Iran attains the bomb, with Egypt, Saudi Arabia, Syria and Turkey developing their own nuclear weapons capability and Iran instigating Sunni-Shia conflict throughout the world." He also described a "near-term conventional war with Iran as clearly preferable to the long term consequences of a nuclear-armed Iran." The UAE under Sheikh Mohammed has rapidly modernized and expanded its military, with its special forces getting experience in Afghanistan. It now fights alongside Saudi Arabia against Yemen's Houthi rebels, has reportedly hired Colombian mercenaries and has over 130 fighter jets.
Iran has both a standing military and its paramilitary Revolutionary Guard. Estimates put its troop strength at over 500,000, with hundreds of thousands more in reserve. Its air force has suffered from Western sanctions, now having a fleet of mostly pre-1979 American fighter jets. However, the Guard maintains an arsenal of ballistic missiles capable of reaching across the wider Middle East, as well as increasingly modern drone fleet. Iran mustered human wave attacks during its 1980s war with neighboring Iraq. It also has additional reach through proxy forces throughout the region and has used that to its advantage over the years. It also has developed cyberwarfare capabilities.
Hezbollah, the most powerful and effective among Iranian-backed militias in the region, has kept quiet in recent days as tensions have spiked. Its leader, Hassan Nasrallah, however, has said in the past that Iran would not stand alone in any future confrontation with the U.S. The group, formed to combat Israel following its invasion of Lebanon in 1982, has tens of thousands of rockets and missiles that can reach deep into Israel, as well as thousands of disciplined and battle-hardened fighters. Hezbollah has fought alongside government forces in Syria for more than six years, gaining more experience and expanding its reach. Iran could mobilize Hezbollah to strike at Israel, which would dramatically expand the battlefield but likely draw retaliation that would be devastating for Lebanon. Hezbollah says it is not seeking another war with Israel, and it is not likely to join in any regional confrontation — at least not in the early stages — unless provoked. Hezbollah has lost hundreds of fighters in Syria, exacting a heavy toll on the Shiite community from which it draws most of its support. It is also feeling the crippling U.S. sanctions imposed on the group and its sponsor, Iran.
SHIITE MILITIAS IN IRAQ
Iran can count on the loyalty of tens of thousands of Shiite fighters in Iraq, militias collectively known as the Popular Mobilization forces, or Hashd al-Shaabi in Arabic. Trained, financed, and equipped by Iran, the militias battled U.S. forces in the years after the 2003 invasion and remobilized to battle the Islamic State group a decade later. The groups include Asaib Ahl al-Haq, Kataeb Hezbollah and the Badr Organization, all three led by men with close ties to Gen. Qassem Soleimani, the leader of Iran's elite Quds Force and the architect of Tehran's regional strategy. The militias were incorporated into Iraq's armed forces in 2016. Together they number more than 140,000 fighters, and while they fall under the authority of Iraq's prime minister, the PMF's top brass align politically with Iran. U.S. forces and the PMF fought side-by-side against IS militants after Iraq's parliament invited the U.S. back into the country in 2014. But now that the war is largely concluded, some militia leaders are calling on U.S. troops to leave again, threatening to expel them by force if necessary. On Sunday, a rocket was fired into Baghdad's heavily fortified Green Zone, landing less than a mile from the U.S. Embassy. No group claimed responsibility, but an Iraqi military spokesman said the rocket was fired from eastern Baghdad, where many Iran-backed groups are based.
YEMEN'S HOUTHI REBELS
Yemen's Houthi rebels seized the country's capital, Sanaa, in 2014. It later pushed the country's internationally recognized government nearly into the sea in Aden before a Saudi-led coalition launched a war against them in March 2015. Since then, the Houthis have been effective guerrilla fighters with small arms, but also have launched ballistic missiles into neighboring Saudi Arabia. They've flown drones into Patriot missile batteries and exploded bomb-carrying ones over a military parade and a Saudi oil pipeline from a distance. U.N. experts believe their newest drone likely has a range of up to 1,500 kilometers (930 miles). They also have arms seized from Yemeni military barracks, including missiles fired at an Emirati ship, commercial boats and even once against a U.S. warship.
Gambrell reported from Dubai, United Arab Emirates; Karam reported from Beirut and Federman reported from Jerusalem.