A timeline of the intensifying Israel-Hezbollah-Iran conflict

Iran launched missiles at Israel on Tuesday in an attack it said was retaliation for a wave of assassinations carried out by Israel over the last several weeks targeting Hezbollah, an Iran-backed, Shiite Muslim political party and militant group based in Lebanon.

Iran has also said the attacks were for Israel's extensive attacks on Hezbollah, the destruction in Gaza as well as the assassinations of key Hamas and Hezbollah leaders, including Hamas' political leader Ismail Haniyeh.

Hezbollah has clashed with Israel for decades, going back to Israel's occupation of southern Lebanon in 1978, according to the Council on Foreign Relations, a New York City-based independent think tank.

Hezbollah and Israel have repeatedly attacked each other, trading fire across the Lebanese-Israeli border for months.

Tuesday’s strike marks the latest development in an intensifying series of attacks in the region.

Here’s a look at the timeline of the recent conflict:

On Oct. 8, 2023, Israel invaded the Palestinian territory of the Gaza Strip. The invasion was in retaliation for Hamas' terror attack on Israel on Oct. 7, where Hamas killed roughly 1,200 people and around 250 others were taken hostage, according to the Israeli government.

Hezbollah then began renewed attacks on Israel in opposition to the Gaza invasion, and since Oct. 8, the two sides have been trading attacks with increased intensity in recent months.

In Gaza, about 41,638 people have been killed amid Israeli attacks on the region, according to the Hamas-run Gaza Ministry of Health. Hezbollah has said it will continue its attacks against Israel until the Israel Defense Forces withdraw from Gaza.

Hezbollah controls much of the Shiite-majority areas of Lebanon, including parts of the capital, Beirut. Iran has long been known to provide support, training and weapons to the group.

The IDF said that its special operations teams have been operating in southern Lebanon since November. Hezbollah has denied this and says the IDF has not crossed Lebanon's border.

Cease-fire negotiations to end Israel's ongoing war in Gaza and return Israeli hostages have stalled after repeated attempts by the U.S. and others to mediate a deal, and Israeli Prime Minister Benjamin Netanyahu has declined a cease-fire proposal concerning its operations in Lebanon.

The conflict intensified with the detonation of Hezbollah communication devices in Lebanon and Syria. Thousands of people were injured and dozens were killed across Lebanon and Syria by remotely detonated pagers on Sept. 17, according to Lebanese officials. ABC News sources confirmed it was an Israeli covert operation.

The Israeli military also ramped up its airstrikes in Lebanon in recent weeks, including striking thousands of apparent Hezbollah targets in southern Lebanon and killing more than 1030 people and injuring thousands more,according to the Lebanese Ministry of Public Health. Israeli officials said they believe about 30 top Hezbollah leaders have been killed.

On Sept. 26, 2024, Iranian Foreign Minister Abbas Araghchi told reporters on the sidelines of the United Nations General Assembly in New York City that Iran "will not remain indifferent in case of a full-scale war in Lebanon."

Araghchi also warned that Israel's "crimes will not go unpunished" and said the Middle East region "risks full-scale conflict" if the U.N. Security Council does not "act now to halt Israel's war and enforce an immediate ceasefire."

On Sept. 30, the IDF announced it had begun a ground incursion into Lebanon. The IDF described the operations as "limited, localized, and targeted ground raids based on precise intelligence against Hezbollah terrorist targets and infrastructure in southern Lebanon."

On Oct. 1, Iran launched missiles into Israel. The Islamic Revolutionary Guard Corps (IRGC) said the missile attack was retaliation for different assassinations carried out by Israel.

President Joe Biden said on Oct. 1 that the U.S. is prepared to help Israel defend against the Iranian missile attack.

ABC News' Meredith Deliso, Matt Gutman, Nadine El-Bawab, Emily Shapiro, David Brennan, and Julia Reinstein contributed to this report.