Israel targeted nuclear and military sites in Iran in airstrikes early Friday morning.The strikes are a major escalation that threatens to expand into a wider regional conflict.These are five key questions in the wake of Israel's air war.

An aggressive counterattack risks escalation. But giving in to U.S. and Israeli demands is an unlikely alternative.

In response to Israel’s attack, Iran fired back with more than 100 drones. NBC News’ Chief International Correspondent Keir Simmons reports more. Former NATO Supreme Allied Commander retired Gen. Wesley Clark and Senior Fellow at the Carnegie Endowment for International Peace Aaron David Miller join Ana Cabrera to examine the possibility of further attacks.

Iran began its retaliation campaign early Friday, after warning Israel it would pay a “heavy price” for its attack.

Iranian President Masoud Pezeshkian told his Russian counterpart Vladimir Putin that Israel’s aggression against Iran on Friday will undoubtedly receive an appropriate response.

Johnson affirmed the U.S. and Israel's shared goal of preventing Iran from acquiring nuclear weapons. Israeli Prime Minister Benjamin Netanyahu stated the operation aims to counter Iran's threat to Israel's existence.

Airlines cleared out of the airspace over Israel, Iran and Iraq early on Friday after Israel launched attacks on targets in Iran, Flightradar24 data showed, with carriers scrambling to divert and cancel flights to keep passengers and crew safe.

Airspace was closed over Israel, Jordan, Iran and Iraq on Friday after Israel attacked Iran with a wave of airstrikes.