When Prime Minister Benjamin Netanyahu addressed Israelis late on Monday night, he knew the army had lost 10 soldiers in the course of the day, although news of five of those fatalities had not yet been made public. That made Monday Israel’s darkest day to date in the three weeks of Operation Protective Edge, with the IDF toll rising to 53.

With Hamas gloating, Netanyahu’s brief remarks were reported in some quarters as presaging an expansion of the ground offensive, presumably taking the army deeper into Gaza — into the even-more treacherous neighborhoods where the Hamas leadership, many of its gunmen, and much of its weaponry sit in fortified underground bunkers and tunnels. But actually the prime minister was deliberately ambiguous. He said Israel wouldn’t end the operation until the threat posed by Hamas’s cross-border tunnels had been dealt with, and he reminded Israelis that he’d told them all along this could be a lengthy operation, but he gave no definitive indication that the real battle to destroy Hamas was about to begin.

Indeed, it has been clear since the days before this conflict began that Netanyahu has not wanted to launch a full-scale war against Hamas. He repeatedly offered “quiet for quiet” when the rocket fire first escalated, immediately accepted the Egyptian ceasefire proposal two weeks ago, agreed to a series of “humanitarian time-outs” which were then breached by Hamas over recent days, and waved away what he called the “background noise” from those, like Foreign Minister Avigdor Liberman, who have been loudly urging him to smash Hamas and deriding him for his hesitancy.

Nobody can imagine for a moment that Netanyahu does not consider Hamas the embodiment of Islamic extremist evil. Nobody can doubt that he takes seriously Hamas’s declared goal of destroying Israel. Netanyahu does not believe for a second that Hamas can be reformed. Netanyahu does not believe any conceivable post-conflict framework could achieve the demilitarization of Gaza if Hamas remains largely intact. He knows all too well how Hamas has strengthened its capacity to do Israel harm over the seven years since it seized control of Gaza, and that it will only strengthen further if it is able to do so after this conflict. It was he who warned that the tunnels would have been used to “catastrophic” effect against the residents of Gaza-adjacent communities had they not been tackled now. It was he on Monday night who declared it untenable for Israelis to be faced with the threat of “death from above” by rocket fire and “death from below” via the terror tunnels.

So why, from a prime minister clear-eyed about the danger Hamas poses to Israel, and urged by his right-wing base to approve more intensive military action, this manifest disinclination to send the IDF “all the way”?

One possible explanation: He believes that for all Hamas’s swaggering, it is in real trouble — not militarily, where its key capacity has not been significantly harmed, but in terms of its credibility in Gaza and thus its likely standing when the guns fall silent. That Gazans loathe Israel is a given. But might they also increasingly loathe Hamas for bringing Israel’s military force down upon them? And might a weakened Hamas be forced to accept the return of Mahmoud Abbas’s Palestinian Authority to Gaza, with the possibility of the “sustained calm” for Israel that Netanyahu set as his opening objective for this conflict?

Another possible consideration: He knows how heavy the IDF losses will be in a full-scale ground offensive. Israel enjoys air supremacy over Gaza. On the ground, things are very different. Israel lost five soldiers on Monday who were killed by Hamas gunmen emerging from a tunnel the IDF had identified, partially demolished, and thought it had secured. Even in those most favorable of conceivable circumstances, the infiltrators fatally surprised the army. Deep in Gaza, Hamas enjoys a home field advantage. Its killers are waiting. The IDF is a highly motivated, well-trained and well-equipped fighting force. Hamas’s home advantage notwithstanding, Israel’s ground troops are certain to kill many more of the enemy’s gunmen than they lose. But be the ratio 5:1, 10:1, or 20:1, Israel will bleed, and quite apart from his own anguish at such a prospect, the prime minister may be concerned that the public mood will turn radically before Hamas is defeated.

Alternately, Netanyahu may be highly concerned about the consequences of a successful ground invasion, leaving Israel back in control of 1.7 million very hostile Palestinians.

A further possible explanation — to my mind a relevant one: Netanyahu is watching the boiling Middle East aware of the ease with which one active military front, in Gaza, can become two, three or more. In South Lebanon, Hezbollah has 10 times as many rockets as Hamas had three weeks ago, with longer ranges, greater accuracy and bigger warheads. It has stayed out of this conflict so far; there are no guarantees it will continue to do so. Its sponsor-in-chief, Iran’s Ayatollah Khamenei, has been urging Muslims everywhere to arm the Palestinians against the vicious Zionist enterprise. Thus far, he has steered clear of calling Hezbollah into action — testament, perhaps, to the ongoing deterrent effect of the 2006 war. Closer to home, last weekend saw nine Palestinians killed in clashes in the West Bank, after the masses were exhorted by Hamas to unleash a Third Intifada. There were riots in parts of East Jerusalem, too.

Also worth remembering, as Netanyahu holds back, is his unyielding focus on the Iranian nuclear weapon drive. If necessary, he has said time and again, Israel will act alone to stop Iran attaining the bomb. Netanyahu emphatically considers the Iranian program an existential threat to Israel, and is anything but confident in the will of the international community to avert it. Becoming deeply embroiled in a major, bloody war in Gaza is a distraction he may be intent on avoiding. He may also be concerned at exhausting such tolerance for Israeli military action as still exists internationally over Gaza — where the scenes of devastation, death and helplessness effortlessly trump the most articulate efforts to explain why this is all Hamas’s fault — when he may need it over Iran.

Only the prime minister and those closest to him know which if any of these considerations, or others, are centrally impacting his decision-making. Netanyahu is anything but a fool — and nor, for that matter, are the minister of defense and the IDF chief of staff who are stewarding this conflict with him and, unsurprisingly, showing no signs of dissent. He knows he can’t leave the IDF treading water in Gaza — partially deployed, relatively exposed.

But whatever choices he now makes, there can be no doubt: Netanyahu, who opposed Israel’s 2005 disengagement from Gaza, did not want to order its re-invasion. Which raises the question: What does he have in mind?