On Sunday, OC Southern Command Maj.- Gen. Tal Russo was standing inside Mahaneh Amitai, a base adjacent to the Kerem Shalom border crossing, when he suddenly heard shooting. It took a minute or two for the IDF to realize that the shooting was coming from the other side of the border, in Egypt.Russo had a feeling that something was going to happen that evening, which is why he decided to visit Amitai, the home base for the IDF’s Beduin Reconnaissance Unit. He later referred to the information passed on to him from Military Intelligence and the Shin Bet (Israel Security Agency) regarding a possible attack as being vague and unclear, without anything to help him determine where the attack would take place along the 230-kilometer-long border for which he is responsible.But it turned out that Russo had made the right decision when he ordered the evacuation of a number of watchtowers IDF soldiers had manned along the border a day or two earlier out of fear that they would come under missile fire.While the watchtowers were not attacked, the border fence directly beneath one of them was blown up and was the point where the armored vehicle and the explosives-laden pickup truck crossed into Israel.Had soldiers been inside, who knows what could have happened.For Russo, the success in thwarting the attack on Sunday night – the infiltration ended with eight dead terrorists and no casualties in Israel – was more than just a sigh of relief.Last August, Russo came under fire from Defense Minister Ehud Barak after he decided not to close Road 12 despite intelligence that an attack was in the planning.The attack, which took place near the Netafim crossing, took Russo completely by surprise: it took place in the middle of the day while he had prepared his units for an attack at night and the terrorists crossed into Israel right under an Egyptian military post – the exact spot where Russo had predicted they would steer clear of. Eight Israelis were killed in the attack and Barak publicly criticized him for leaving the road open.For Russo, though, this is anything but comforting.While both last year’s and this year’s attacks took the IDF by surprise, there is one major difference: the IDF this year is looking more at Sinai than it was last summer, and soldiers stationed along the border are constantly on high alert.The main difference, one officer said this week, was in the number of terror alerts the IDF has on any given day from Gaza and from Sinai. Today, there are more from Sinai. As a result, Russo knows that it is only a matter of time before the same group or a different one tries to launch another attack.For Israel, the attack launched on Sunday raised a number of questions. Firstly, officers openly admitted that they were impressed with the attack, calling it “sophisticated” and “ambitious.”In total, some 35 armed men are believed to have stormed the Egyptian base just south of Rafah, where they killed 16 soldiers, stole an armored vehicle, infiltrated Israel and then drove on a civilian road for two kilometers before being hit by missiles and shells fired from an aircraft and nearby tanks.One of the main questions on officers’ minds was why the terrorists decided to kill the 16 Egyptian soldiers and why they didn’t prefer to just tie them up if all they were after was the armored vehicle which they then used to storm the border? The question is all the more relevant considering the unprecedented military action the Egyptian government is taking now in Sinai – including airstrikes in the peninsula for the first time since the 1973 Yom Kippur War – that would have likely not had happened had 16 soldiers not been slaughtered by the terrorists.This led the IDF and the Shin Bet to conclude that the group behind the attack – the identity of which is still not known – was looking to send a clear message not just to Israel, which was the primary target, but also to Cairo regarding its existence as a new and formidable player in the region.The group, Israel believes, also wanted to raise tensions between Israel and Egypt – and what better way to do that than to launch a cross-border attack with casualties on both sides? While Israel does not yet seem able to put its finger on the exact culprit behind the attack, it has a pretty good idea who the attackers were – mostly Beduin from Sinai as well as possibly some other Arabs from throughout the Middle East, including graduates of the recent wars in Libya, Afghanistan and Iraq who have now moved on to a new target.The fact, for example, that most of the attackers were found wearing explosive bomb belts, ruled out the possibility that they wanted to kidnap a soldier.Instead, it appears, they wanted to kill as many people as they could.The IDF, though, does not have such high hopes for the current Egyptian military operation, which seems to be motivated mostly by a desire for revenge and less by a real interest in weeding out the terrorist infrastructure that Egypt has allowed to grow under its nose in Sinai.Israel will likely continue to refrain from taking military action of its own against terrorist targets in Sinai, in contrast to what it does, for example, in the Gaza Strip; but if an attack does succeed with a significant number of casualties, it will be difficult to see how the government will be able to restrain itself for much longer.Prime Minister Binyamin Netanyahu seemed to be hinting at this on Monday when he toured the scene of the attack with Barak.Borrowing from his usual rhetoric on Iran, Netanyahu declared: “Israel can only rely on itself… and will continue to do so.”What he meant by this was unclear, although in previous cases when he said so it was in relation to possible preemptive military action against Iran’s nuclear facilities, which he has publicly admitted to be seriously considering. It might be that Netanyahu’s veiled threat was what helped spur Egyptian President Mohamed Morsy into action on Tuesday with the new operation in Sinai.If that is the case, then Netanyahu can claim another victory in the world of Israeli saberrattling.The same has happened with Iran, which is facing escalating diplomatic isolation and economic sanctions, largely due to US and overall Western fears that Netanyahu is planning to attack – something they would like to prevent.Israel, by the way, has raised the situation in Sinai in all of its recent talks with the American officials who have come to Jerusalem in recent weeks.What Israel explains is quite simple: a successful attack from Sinai could lead to something far more dramatic from a regional point of view. The Americans got the point and it was no coincidence that both Secretary of State Hillary Clinton and Secretary of Defense Leon Panetta came to Israel just after stopping off in Cairo.Even Netanyahu’s political adversaries are impressed by his poker face and find it difficult to tell what he plans to do with regards to Iran. Many analysts and political observers seem to think the chances for an attack are something like 50-50. Others believe the chance Netanyahu will launch an attack is around 20 percent.While the odds are interesting, they tend to miss the real question at the heart of the issue: whether Israel can trust the United States. It is important to stress that Israel and the US share the same intelligence assessments on Iran. Both, for example, agree that Iran is not yet building a bomb and both agree that once Ayatollah Ali Khamenei makes the decision to do so, it will take around a year for Iran to build a bomb.The disagreement is whether Israel can trust the Obama administration to take the necessary action to stop Iran if it gets to the breakout stage and begins building a bomb. Israel fears that the world might miss the opportunity and then it will be too late. The US counters that its intelligence hold on Iran is good and that it will know when and if that happens.Until that decision is made, though, Israel will have its hands full keeping an eye on Sinai and waiting for the next attack to come. No one currently knows when that will happen but, like with Iran, the odds aren’t looking too good.