Why is Iran moving to the stage of missiles with heavy warheads?

Iran has announced it will no longer launch missiles with warheads weighing less than one ton, a shift intended to increase the destructive impact and deterrent capability of its ballistic missiles.

“Iran has escalated its military messaging amid the rising confrontation with the United States and Israel, announcing that it will no longer launch missiles whose warheads weigh less than one ton — a step that reflects a move to increase the destructive impact of its ballistic missiles and its deterrent capability”

Al-Jazeera Net

The announcement came from the commander of the Aerospace Force of the Islamic Revolutionary Guard Corps, Brigadier General Majid Mousavi.

Al-Jazeera Net

He said the attacks in response to Washington and Tel Aviv "will not stop for a single moment."

Mousavi said future missiles will carry warheads of no less than one ton, with increased launch frequency and a widening scope of missile waves.

The Revolutionary Guard announced late Monday–Tuesday night the launch of missiles carrying one-ton warheads during the 33rd wave of Operation "Al-Wa'd al-Sadiq 4" toward Israeli and American targets.

Military expert Brigadier General Hassan Jouni told Al Jazeera that the statement reflects Iran's defensive doctrine.

He said the doctrine is built primarily around ballistic missiles as the means to balance opponents' air superiority.

Al-Jazeera Net

Jouni said Iran has prepared and built its arsenal around these weapons over many years.

He described escalation in ballistic missile use along three levels.

The first is increasing explosive warhead weight, now at one ton and likely to rise.

The second is using detonation types such as fragmentation or cluster bursts to multiply destructive effect.

The third is improving strike accuracy to hit more sensitive targets.

Jouni also addressed U.S. President Donald Trump's claim about destroying 80% of Iran's military capabilities, saying that estimate was likely based on a slowdown in Iranian missile launches.

“Iran has escalated its military messaging amid the rising confrontation with the United States and Israel, announcing that it will no longer launch missiles whose warheads weigh less than one ton — a step that reflects a move to increase the destructive impact of its ballistic missiles and its deterrent capability”

Al-Jazeera Net

He acknowledged that intensive airstrikes that lasted 11 days "undoubtedly destroyed a large part of Iran's arsenal," but said that none of the parties has precise information about the size of that arsenal and that accurately estimating losses is extremely difficult.

He added that if precise information existed, it would make it possible to locate and target remaining assets more directly.

Since February 28, Israel and the United States have been carrying out attacks on Iran.

The article says those attacks have resulted in hundreds killed and injured.

Al-Jazeera Net

It names the Supreme Leader Ali Khamenei, the defense minister, the commander of the Revolutionary Guard, and other military commanders among those affected, but the article's wording is ambiguous about whether those figures were killed or injured.

The article says Tehran has responded by launching missiles and drones toward Israel and by targeting what it describes as 'American interests' in Arab and Gulf countries.

Those actions have caused deaths and injuries and damage to civilian facilities, including airports, ports, and residential buildings.