Explained: Why Lebanon is pushing to disarm Hezbollah? Can they do it? How is US involved?

Lebanon's cabinet has told the army to draw up a plan to establish a state monopoly on arms in a challenge to the Iran-backed Shi'ite Muslim group Hezbollah, which rejects calls to disarm.

Why is there a push to disarm Hezbollah now?

Israel pummeled Hezbollah last year in a war sparked by the conflict in Gaza, killing many of its top brass and 5,000 of its fighters before a November truce brokered by the United States.

That deal committed Lebanon to restricting arms to six specific state security forces, and further stipulated that it should confiscate unauthorised weapons and prevent rearmament by non-state groups.

In the months since, a new Lebanese government vowed to confine arms across the country to state control, Hezbollah's main arms route was cut when its Syrian ally Bashar al-Assad was ousted in December and Israel attacked its sponsor Iran in June.

The government is facing pressure from Washington and Hezbollah's domestic rivals to act swiftly amid fears that Israel could intensify air strikes on Lebanon.

Despite November's ceasefire, Israel has continued to carry out strikes on what it says are Hezbollah arms depots and fighters, mostly in southern Lebanon.

How is the US involved?

In June, U.S. envoy Thomas Barrack proposed a roadmap to Lebanese officials to fully disarm Hezbollah in exchange for Israel halting its strikes on Lebanon and withdrawing its troops from five points they still occupy in southern Lebanon.

But Hezbollah and its main Shi'ite ally the Amal Movement, led by Parliament Speaker Nabih Berri, say the sequencing should be reversed, with Israel withdrawing and halting strikes before any talks on Hezbollah's arms.

Washington has grown impatient, demanding the Beirut government make the first move with a formal commitment to disarm Hezbollah.

Why is Hezbollah so well-armed?

After Lebanon's 15-year civil war ended in 1990 Hezbollah, founded by Iran's Revolutionary Guards in 1982, was the only group allowed to keep its weapons on the grounds that it was fighting Israel's occupation of the country's south.

After Israel withdrew in 2000 the group did not give up its arms, arguing its ability to fight was still a critical element of national defence against future Israeli aggression.

A ceasefire agreement after a war between Hezbollah and Israel in 2006 was backed by a U.N. resolution demanding the disarmament of all militant groups - but Hezbollah again kept its weapons, accusing Israel of having violated other parts of the truce deal, which Israel denies.

Hezbollah took over parts of Beirut in fighting in 2008, underscoring its dominance. The group exercised decisive sway over state affairs in the following years as its power grew.

What does Hezbollah say and could there be civil strife?

Hezbollah has called the government's decision to ask the army to draw up plans to disarm it a "grave sin" that "fully serves Israel's interest".

Hezbollah chief Naim Qassem rejected each clause in Barrack's roadmap and when he spoke on Tuesday, dozens of motorcycles with men carrying Hezbollah flags drove around the group's stronghold in Beirut's southern suburbs - a show of its enduring strength.

Hovering over any attempt to force Hezbollah to disarm is the spectre of previous bouts of civil unrest, including the 2008 fighting, triggered by the government's attempt to shut down the group's military telecoms network - an important facility for the group, but still less central than its arms.

What are political complications?

Lebanon's power-sharing system apportions public sector posts - including in parliament, the cabinet and other roles - to different religious sects according to quotas.

The system is meant to ensure no sect is cut out of decision making, but critics say it leads to political paralysis.

Shi'ite representation in both parliament and cabinet is dominated by Hezbollah and its political ally Amal.

Two Shi'ite ministers were travelling during Tuesday's cabinet session, and the other two walked out in the final moments as the decision was being taken. Qassem has said any government decision would require a national consensus and may challenge the legitimacy of cabinet decisions taken without Shi'ites.

What happens next?

The cabinet decision gave the army a deadline to submit a disarmament plan to the government by the end of August. Another session scheduled for Thursday will discuss Barrack's proposal.

Some Lebanese parties may keep trying to find a workaround that avoids a confrontation between Hezbollah and the state while warding off heavier Israeli strikes.