Several retired Israeli generals met this week to simulate a ground phase in the battle against Islamic State. They concluded that a joint air and ground operation to destroy the group on two fronts can be executed fairly easily and quickly.

The officers also reached their conclusion based on the assessment that, following last month’s Paris terror attacks, more and more countries will drop their restrictions to combating the jihadist organization.

The officers, who used to hold the most senior positions within the Israel Defense Forces – including in the general staff, air force, navy, ground forces and Military Intelligence – prefer to remain anonymous for the time being. But their professional assessment reflects the best and most current thinking in Israeli defense circles, based as it is on practical experience in conducting campaigns against Hamas and Hezbollah, and deep knowledge of U.S. doctrine and decision makers.

Their brainstorming was convened and moderated by Col. (ret.) Gabi Siboni, who directs the military affairs program at the Institute for National Security Studies, within Tel Aviv University. Siboni is particularly close to the current chief of staff, Lt. Gen. Gadi Eisenkot.

These were the key points identified by the officers:

* There will be two simultaneous theaters of war across the entire front, subject to attack by a double coalition – an Eastern one (in Iraq) led by the United States, and a Western one (Syria) led by Russia. Each will contain Arab forces, in addition to indigenous groups (i.e., Kurdish militias and Syrian rebels), with Jordan, Gulf Cooperation Council members and perhaps Egypt being the obvious Arab candidates.

* The overall source of authority will be the UN Security Council, since Russia will insist on a decision-making body where it holds veto power – so certainly not the NATO alliance. The role of Turkey – an important NATO member that borders the contested ISIS area in Northwestern Syria but is currently in dispute with Russia – is yet to be determined. The operation will have to be planned with two options, with or without Turkey – as it was during the 2003 Iraq War, when incoming Turkish Prime Minister Recep Tayyip Erdogan reversed his predecessor’s position and denied U.S. forces their assumed northern flank.

* The military operation will not set as its goal the destruction of the caliphate concept, but rather, the enemy that calls itself the Islamic State – its leaders, headquarters, forces and infrastructure.

* The economic element of the campaign – hitting the financial, commercial and industrial (oil) assets that enable ISIS’ activity – is complementary to the military part, but not a substitute for the ground offensive.

* While airstrikes with precision munitions have degraded ISIS, reversed its momentum and helped reconquer territory that it occupied, it must be coupled with a ground offensive timed to exploit the success gained from the air. Thus, in both theaters and through the mechanisms of both coalitions, the air-ground operations have to be synchronized for maximum effect.

* ISIS is “an administration with territory” rather than an Al-Qaida-like terror organization, although it also executes terror attacks. It is, therefore, more vulnerable on its home ground, meaning the campaign’s focus must be on the offensive, without neglecting defensive measures in Europe and elsewhere. The self-styled state is a weak enemy that could disintegrate in a manner of weeks or even days under an assault, once its centers of gravity are hit.

* The three centers of gravity are urban objectives – two in Iraq (Mosul, Ramadi) and one in Syria (Raqqa, ISIS’ de facto capital). The Israeli officers say that each city could be overpowered by a divisional combat group, centered around an infantry, marine, paratroop or mechanized division, along with airborne, fire support, engineer and intelligence elements. The two efforts would be commanded by a three-star corps commander, an American one in Iraq (where III Corps commanding officer Lt. Gen. Sean MacFarland has been in charge), and a Russian one in Syria.

* If the officers’ evaluation is correct, and three army/marine divisions will suffice (along with their air and logistics support), the campaign against ISIS would be based on an order-of-battle roughly similar to the one employed by the IDF in 2014’s Operation Protective Edge against Hamas in the Gaza Strip, and somewhat smaller than the ones Israel used during the Second Lebanon War in 2006 and Operation Defensive Shield in the West Bank in 2002.