There are two key questions in terms of military strategy in Gaza: how strong is Hamas? And how is Hamas evolving as a military force? According to leading Israeli analysts, Hezbollah in Lebanon is a potent model.

Amos Harel and Avi Issacharoff say that Hamas has 15,000 men under arms:

The core of Hamas’ “army” is its military wing, Iz al-Din al-Qassam, which the organization sees as its best trained and most disciplined force. It was deployed against Fatah in June 2007 and it will bear the brunt of any engagement with the IDF. Iz al-Din does not generally perform unpopular policing operations (such as the daily suppression of Fatah), instead focusing on preparing for battle with Israel.

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Hamas’ main weapon is its ability to launch dozens of rockets a day at Israel. In the event of an escalation the organization can be expected to try to prove that it can hit more distant targets, such as Be’er Sheva. Ashkelon is liable to suffer massive rockets attacks. In addition, Hamas is likely to target one kibbutz or moshav near the border in an attempt to cause large numbers of residents to leave and weaken Israeli morale. Israel must also be prepared for a surprise from Hamas, a la Hezbollah, ranging from additional tunnels to facilitate abductions to attacks on boats or aircraft and up to attacks on strategic targets in the south.

Yaakov Katz, meanwhile, provides some insight into the Hamas military leadership:

Ahmed Ja’abri is the commander of Gaza City. Ahmed Andour is in charge in the North. Iman Nufal, the commander of central Gaza, is in Egyptian custody after he was arrested last year when he entered Sinai. The two brigades

in the South - one in Khan Yunis and one in Rafah, are led by Mahmoud Sanour and Ra’ad Alatour.

Andour is believed to be Ja’abri’s right-hand man. He was reportedly imprisoned by the Palestinian Authority for five years in the mid 1990s. Together with Ja’abri, Andour was behind the attacks against Fatah militiamen in the summer of 2007 that led to Hamas’s takeover of the Gaza Strip. Ja’abri and Andour are believed to have masterminded the June 2006 kidnapping of Gilad Schalit.

Katz also notes the tactical borrowing from Hezbollah, quoting one official who said:

Hamas has learned a lot from Hizbullah and has adopted many of the Lebanese group’s tactics that were used successfully against the IDF in the Second Lebanon War.

Importantly, Harel and Issacharoff say:

Nevertheless, military experts in Israel and the West believe the IDF is capable of retaking Gaza. Israeli reservations about a broad military operation, therefore, are mainly linked to the question of what happens afterward, when the IDF controls a large area that it doesn’t want and is in constant friction with terrorists and the civilian population.