BEIRUT — There may not be much Iran can do about President Trump’s withdrawal from the nuclear deal, but across the Middle East, it has a variety of ways it can hit back at the United States and America’s regional allies.

Iran has expanded its influence far beyond its borders in recent years, sponsoring an army of tens of thousands of Shiite militiamen spread across Iraq and Syria, all the way to Lebanon. A rocket attack overnight on Israeli positions in the Golan Heights may have been a first salvo, underscoring Tehran’s reach. Israel responded with a blistering wave of missile strikes early Thursday.

Iran also holds enormous political sway in neighboring Iraq and in Lebanon, where its main Shiite ally, the militant Hezbollah group, scored significant gains in weekend elections. In Iraq, two powerful political alliances expected to win seats in parliamentary elections Sunday also maintain strong ties to Iran.

In his speech announcing the U.S. withdrawal from the landmark 2015 nuclear deal, Trump called Iran the “world’s leading state sponsor of terror,” citing its support for “terrorist” proxies and militias such as Hezbollah and Hamas, as well as its activities in Yemen.

The rivalry between Iran and Saudi Arabia has torn the region apart, playing out on regional battlefields and fanning sectarian flames in Iraq, Syria, Lebanon, Bahrain and Yemen. Trump’s decision will likely intensify those confrontations, and could also embolden Israel to step up its own proxy battles against Tehran.

Here is a look at proxy battlefields in Iran’s looming confrontation with the U.S., Saudi Arabia and Israel:

SYRIA AND THE GOLAN HEIGHTS

Any confrontation between Iran and Israel is likely to play out first and foremost on the battlefields of Syria, where Iran has built an extensive network of militias during Syria’s civil war. Advisers from Iran’s elite Revolutionary Guards, as well as trainers, commanders and experts, are stationed at military bases across the country.

It also has spy drones that it can use to attack from the sky. In February, Israel shot down what it said was a drone that contained explosives sent by Iran from an air base in Syria, prompting Israeli airstrikes that killed at least seven Iranians. An Israeli warplane was shot down during the battle.

Israel’s main concern is southern Syria, near the Israeli-controlled Golan Heights, where Tehran has been boosting its presence for years and where it could launch rocket attacks into Israeli territory.

Israel has said it will do what it takes to fend off Iran’s military entrenchment. A series of strikes over the last few months – all blamed on Israel – have struck Iranian assets in Syria and killed Iranian forces there.

The strikes have prompted threats of retaliation from Tehran, and Israel has girded for a response, ordering bomb shelters open in the Golan.

Israel will no doubt strike back after any attack on its territory, a scenario that could spiral into a wider conflict that experts say no side is currently interested in.

With Trump’s backing, Israel may even feel emboldened to take further pre-emptive action against Iranian targets in Syria. Iran’s presence in Syria is no match for Israel’s powerful military, and Iran’s hopes of salvaging the deal and appearing moderate on the world stage may further hinder its ability to strike back.

LEBANON AND ISRAEL

Southern Lebanon’s rolling hills bordering Israel are another arena of influence for Tehran through its Lebanese proxy, Hezbollah.

The frontier has been largely quiet since the last Israel-Hezbollah war in 2006, and Hezbollah is averse to starting a new confrontation in light of its costly intervention in Syria, where it has lost hundreds of fighters.

Launching a new war could endanger Hezbollah’s political support base, including its Shiite constituency, which is wary of another ruinous war with Israel.

Hezbollah has said, however, that it stands ready to defend Lebanon in case of any Israeli attack, and its leader has hinted it may retaliate for repeated Israeli airstrikes in Syria.

Israel has repeatedly targeted weapons shipments destined for Hezbollah, taking advantage of the group’s thinly-spread fighters preoccupied by the war in Syria.

With the war winding down and the group able to refocus on its longtime foe, Israel, the border between the two countries may again heat up. Embroiled in scandals at home, Israeli Prime Minister Benjamin Netanyahu may also seek a provocation to divert attention from his domestic crises.

YEMEN AND SAUDI ARABIA

The war in Yemen, widely seen as a proxy battle between Saudi Arabia and Iran, is another theater Tehran could exploit to inflict pain on its enemies.

Yemen’s Shiite rebels, the Houthis, have fired a series of missiles into neighboring Saudi Arabia during the three-year-old conflict, most recently Wednesday, a day after Trump’s announcement.

The United Nations, Western nations and Saudi Arabia say Iran supplies the Houthis with long-range missiles capable of reaching Riyadh. Iran denies arming them.

GAZA AND JERUSALEM

Confronted by Iranian-allied Hezbollah on its northern border, Israel also faces another enemy to the south with Hamas in Gaza.

Tehran’s relationship with the Islamic militant group has known highs and lows. Hamas developed close ties with Iran after the outbreak of the second Palestinian uprising in the early 2000s, with support – both military and financial – peaking following Hamas’ victory in the 2006 parliamentary elections.

Ties ebbed with the outbreak of the Syrian war in 2011, when the Hamas leadership-in-exile left Syria amid President Bashar Assad’s crackdown on Sunni Muslim rebels, many with ideologies similar to those of the Muslim Brotherhood, the parent movement of Hamas. Ties with Iran have since somewhat recovered, and Hamas is believed to again get funding from Iran.

Since late March, Hamas has been staging weekly mass protests meant to break a stifling, decade-long Israeli-Egyptian blockade on the impoverished territory. Thousands of Palestinians have demonstrated along Israel’s border fence with Gaza.