Damascus — A CBS News team drove through a Syrian military airbase on the outskirts of capital city Damascus Monday, and the devastation caused by Israeli air strikes was abundantly clear. Israel has said it’s determined to destroy weapons and other military hardware that ousted dictator Bashar al-Assad and his father spent half of a century accumulating, before it can fall into the hands of extremists.

The Israeli military has pounded Syrian military infrastructure relentlessly since Assad fled to Russia earlier this month — forced out by a shock rebel offensive after a decade of civil war that had, until about two weeks ago, largely ground to an apparent stalemate.

The damage inflicted on Assad’s old war machine has been staggering. One strike overnight in the coastal city of Tartus, for instance, was so massive that the Syrian Observatory for Human Rights monitoring group quoted a scientist in Turkey as saying it had registered on the Richter scale as the equivalent of a category-3 earthquake.

Until Moscow’s ally Assad fled from Syria, Russia maintained its only major naval base outside of Russian territory in Tartus. Satellite imagery (below) showed most of the Russian ships disappearing from the Tartus port quickly after Assad fell, but the Russian Ministry of Defense said Monday that it was still figuring out what to do about its military hardware and personnel in the country, in talks with the country’s new de-facto rebel rulers.

Israel’s military, meanwhile, says it has laid waste to most of Assad’s heavy weapons and air defenses. In a statement on Monday, the Israel Defense Forces said that in recent days its fighter jets had “inflicted severe damage on Syria’s most strategic weapons: fighter jets and helicopters, Scud missiles, UAVs, cruise missiles, surface-to-sea precision-guided missiles, surface-to-air missiles, surface-to-surface missiles, radars, rockets, and more.”

The IDF said its strikes had destroyed “over 90% of the identified strategic surface-to-air missiles” of the ousted regime.

The lightning takeover of Syria one week ago by the rebel group Hayat Tahrir al Sham, or HTS, has also seen Israeli forces carry out a land incursion that stretches past the occupied Golan Heights region into a previously demilitarized buffer zone inside Syria.

Ahmed al-Sharaa, the head of HTS and Syria’s new de-facto leader, has criticized what he described as Israel’s “uncalculated military adventures,” and said he and his group — which, before publicly distancing itself from extremist ideology was an al-Qaeda affiliate — was more interested in state-building than opening another conflict with Israel.

The targeting of Syria’s military sites has also revealed deep neglect by Assad. Years of corruption and a decade of civil war had hollowed out the nation’s armed forces, contributing to his regime’s collapse. Much of the hardware left behind by his forces when they surrendered to the rebels or simply shed their uniforms and ran away is old and clearly lacking maintenance.

Assad’s office issued the first statement attributed to the deposed leader since he was forced to flee from his country, meanwhile. In it, he claims he never considered resigning nor fleeing, but that he took shelter in the Russian-run air base at Hmeimim as the rebels closed in, and when that facility came under a sustained drone attack, he says an evacuation was ordered on Dec. 8, the day after the HTS rebels took the capital Damascus.

He said he eventually left for Russia as there was nothing else he could do in Syria, lamenting the country’s fall “into the hands of terrorism.”

The statement was posted to the Syrian Presidency’s official channel on the Telegram messaging app, with a note saying it had been posted after several unsuccessful attempts to release it through Arabic and international media outlets. The statement was deleted relatively quickly from the Telegram channel, however, without any explanation, before reappearing there and on the presidency’s Facebook page.

While the wider international community is still trying to figure out how to deal with HTS, which has said it will respect Syrians all of religions and appears determined to be viewed as a secular interim administration — though it has not said what will come next for the country after a three-month transitional period — Israel and the U.S. have remained focused largely on securing Assad’s stockpiled weapons.

For Israel, that has meant the most ferocious airstrikes carried out in Syria in years, and they continued on Monday, just over a week after Assad’s sudden departure.

Whoever does end up in control of Syria will inherit a military infrastructure largely in tatters. Judging by the IDF’s statement on Monday, claiming its strikes amounted to “a significant achievement for the Israeli Air Force’s superiority in the region,” that could be exactly as intended.

Imtiaz Tyab

Imtiaz Tyab is a CBS News correspondent based in London and reports for all platforms, including the “CBS Evening News,” “CBS Mornings,” “CBS Sunday Morning” and CBS News 24/7. He has extensive experience reporting from major global flashpoints, including the Middle East and the war on terror.