Israel's Operation Pillar of Defense, after three days of air strikes on Hamas targets in Gaza, could be entering into a new phase of a larger ground invasion. While the war has been dissected six ways to Sunday, there are still gaping holes in our understanding of it, and several questions remain unanswered. Here are eight of them.

1. Was there an Israeli intelligence failure? There is reason to believe that the Israelis were surprised that so many Iranian-made Fajr-5 missiles had found their way into Gaza. Of course, the Israelis cannot account for every single item smuggled through the tunnels connecting the Sinai Peninsula to the Gaza Strip. And the Israelis appear to know exactly what they are hunting for. But the existence of these rockets -- which one senior Israeli intelligence official calls "game changers" -- is a red line for the Israelis. The very fact that they made it into Gaza without being intercepted or destroyed, and that some have subsequently been fired deep into Israeli territory, represents a failure on some level. This could prompt an official inquiry in Israel, where the brass put a premium on learning from mistakes.

2. Did Turkey, Qatar, and Egypt ever have a handle on Hamas? In recent months, Turkey, Qatar, and Egypt, all closely aligned with the Muslim Brotherhood, have drawn closer to Hamas, which is itself a splinter of that group. These three governments have, in one way or another, been working to politically rehabilitate the Islamist movement and integrate it into the new regional order of the Arab Spring. From all appearances, Washington tacitly approved of this; it certainly did not publicly oppose it. The assumption was that, in light of a precipitous drop in Iranian financing and Hamas' subsequent departure from its headquarters in Syria, the group was perhaps prepared to evolve into a more pragmatic entity. With this recent round of violence, and the use of Iranian long-range missiles, we can draw two broad conclusions: Either Hamas' new patrons are behind its latest violence, or they were blindsided by it. If the latter, did they ever have Hamas under control?

3. Did Iran ever relinquish its grip on Hamas? To put it another way, the reports of the demise of the Axis of Resistance (Iran-Syria-Hamas) may have been greatly exaggerated. The ties between Iran and Hamas' military apparatus, the Izz al-Din al-Qassam Brigades, date back to the early 1990s, when Hamas trained in Sudan with Iranian cooperation and assistance. With the knowledge that Iranian Fajr-5 missiles made their way to Hamas, it is reasonable to wonder if Iran ever left the scene.

4. Did the Israelis target a cache of Fajr-5's in Sudan? Speaking of Sudan, it is widely believed that the Israeli Air Force targeted an Iranian weapons factory in Khartoum last month. Were the Israelis targeting Fajr-5 rockets there? Sudan has long been known to serve as a point of origin for Middle East smuggling routes delivering weapons to Gaza. After that operation, it is possible that Israel realized that a number of those "game-changer" missiles had already reached Gaza, suggesting the aforementioned intelligence failure. Was Gaza part two of a two-part operation that began in Sudan?

5. Will Hamas Upstage the PLO? Even with an arsenal of more lethal rockets in its possession, Hamas has no way of winning a war with Israel. If past is prologue, Hamas' leaders know that drawing Israel into conflict will elicit punishing reprisals. So why bother? One plausible explanation is that the war is just as much about Hamas' domestic arch-rivals, the PLO, as it is about Israel. The PLO is preparing to upgrade its mission at the United Nations later this month, and in the process, claiming to speak for the Palestinian people as a whole. This current round of violence steals the thunder of the PLO; has anyone even talked about the U.N. maneuver since this round of violence erupted? It also sends a pointed message: while the PLO concocts crafty legal schemes in New York, Hamas is doing battle with Israel in the name of the Palestinian cause. Was this the intended message? If so, Washington needs to be paying closer attention to what's happening on the ground.

6. Where's Washington? Despite long-standing tensions between President Barack Obama and Israeli Prime Minister Benjamin Netanyahu, the White House has come out in full support of the Israeli operation in Gaza, citing Israel's right to respond to the hundreds of rockets that Hamas and other jihadis have fired off in recent days. Admittedly, many administration officials appear to be in Asia right now, but the overall message is a green light for Israel. How long will this support last? 

7. Will this impact the Israeli elections in January? Netanyahu detractors charge that the Israeli leader is using the operation in Gaza as a means of increasing voter support ahead of the upcoming elections. In reality, Bibi is the front-runner by a wide margin, and scarcely needs to rally the Israeli public around the flag. If anything, military missteps could weaken his position. As a shrewd student of Israeli politics, Bibi has undoubtedly been weighing the costs of the Gaza operation every step of the way. The Israeli voting public will tell him how he did in about two months' time.

8. Can a ceasefire last? On Friday, Israel's ambassador to Washington, Michael Oren, stated that the Israelis had knocked out most of the long-range missiles they were hunting, indicating that perhaps the primary mission had been accomplished. The Israelis say they want a ceasefire, even as they call up 75,000 ground troops. They say it all depends on Hamas halting the rocket fire. But even if the two primary actors agree, will the other factions in Gaza acquiesce? The Iran-sponsored Palestinian Islamic Jihad and Popular Resistance Committees, along with Salafi groups and even the al-Aqsa Martyrs Brigade -- a splinter of the secular Fatah faction under PLO leader Mahmoud Abbas -- have been firing rockets on a freelance basis. Will they continue to fire on Israel even if Hamas halts? If so, the conflict could last a lot longer.