President Obama might not be the only leader whose self-imposed red lines are drawn in disappearing ink. Until very recently, some were thinking that Benjamin Netanyahu might be predisposed to the same behavior.

Netanyahu has been arguing for years that Iran – despite protestations to the contrary – is intent on developing nuclear weapons and the means to deliver them both near to and far from the Persian homeland. From the Knesset to the halls of the UN to the Oval Office, Netanyahu has preached that the Iranian nuclear quest is a threat to the civilized world, but of course particularly to Israel. He exhorts the world community, and especially the US, to halt the Iranian drive for nuclear weapons capability; and he promises in the most forceful terms that if others will not act, then Israel will.

In a similar vein, Netanyahu has given eloquent speeches excoriating the evil practices of the Gaza-based terrorist organization, Hamas. In the same venues in which he lambasts Iran, Netanyahu passionately describes the murderous designs of Hamas and how the Israelis will thwart those intentions; indeed, how Israel will destroy Hamas if provoked sufficiently.

Well, if more than fifteen hundred rockets fired by Hamas from Gaza into almost every Israeli community is not sufficient provocation, then one wonders what is. Moreover, the latest provocation is exactly that – the latest. For more than decade, Hamas has engaged in rocket attacks, kidnappings, assassinations and many other forms of terror directed at the Jewish State. Periodically, Israel administers a harsh, but short, and in many ways restrained, military response. The international community says, "Tsk, tsk" and prevails upon both sides to cease fire. The calm lasts a brief period whereupon Hamas resumes its cross-border aggression, and gradually escalates its terrorist actions. The cycle repeats.

Everyone, absolutely everyone, understands that the only way that Netanyahu can fulfill his promise to silence Hamas is by reconquering Gaza. The Israelis could do so, but at great cost in casualties on both sides. Netanyahu, despite his eloquent assertions that he will do whatever is necessary to silence Hamas, has – until this past week -- seemed unwilling to incur that cost. When Deputy Minister Danny Danon said so publicly, Netanyahu summarily cashiered him. But Danon was merely pointing out what many were thinking.

In fact, as events have unfolded, it is clear that more than just Danon in Netanyahu's cabinet subscribed to the view that the Prime Minister engaged in perhaps too much talk and too little action. Those suspicions have likely been allayed by Israel's entry into Gaza.

And yet, it is still unclear how indelible the ink on Netanyahu's red line vis-à-vis Hamas really is. According to his words, the goal of the Israeli incursion into Gaza is not the destruction of Hamas, but rather the rendering of that terrorist organization's power sufficiently impotent so as to ensure no attacks from Gaza for a "sustained period." I have no doubt that the IDF can achieve that objective. I also have no doubt that if Hamas remains the governing force in Gaza, it will be able to reconstitute the threat it poses to Israel. It might take years instead of months; but if Hamas is not destroyed, it will eventually recover its dangerous potential. The period of the cycle will lengthen, but the cycle will recur.

Netanyahu is an Israeli hero. If one counts only his achievement of almost single-handedly converting Israel's basket-case socialist economy into the free market dynamo it has become, it would suffice to cement his place among the Zionist giants of the last hundred years. His leadership and ability to unify the Israeli people are also testament to his greatness. Finally, his eloquence in describing the fundamental differences between the freedom and rule of law present in western democracies, and the barbaric, tyrannical forces arrayed against the West in the Islamic fundamentalist world, is without equal. His 1986 book Terrorism: How the West Can Win is representative of his masterful arguments.

But as the years have passed, and Israel under his leadership has failed to attack the Iranian nuclear facilities, doubts have arisen about his resolve. His seeming unwillingness to deliver a fatal blow to Hamas reinforces those doubts. The events of the coming days should resolve the doubts – one way or the other. It is important to resolve them now. For surely, the Iranians are watching carefully and might conclude that Netanyahu has no intention of attacking Iran's nuclear facilities. One supposes that the new "Islamic State" and its mad caliph are also paying attention – not to mention all the other bad apples in Israel's neighborhood.

A century of history has proven that the Arab/Muslim world does not and will not accept the existence of a sovereign Jewish State in the Umma. The Muslim word is willing to use any means, of course including terror, to obliterate Israel. The Israelis understand this. It has compelled them to fight many wars in order to maintain their existence. The sacrifices the Israelis have made in these efforts have been enormous. The Israelis would like, most fervently, to not have to continue making those sacrifices. Alas, harsh (even if eloquent) words and limited military reactions will not dissuade Hamas and its allies from their genocidal intentions. Unfortunately, much more severe action by Israel is required.

Ron Lipsman, Professor Emeritus of Mathematics at the University of Maryland, writes about politics, culture, education, science and sports at http://ronlipsman.com. Follow him on Twitter @rlipsman