Away from the cameras, pomp and fanfare surrounding US President Barack Obama’s historic visit to Israel, urgent security issues will dominate discussions between him and Prime Minister Binyamin Netanyahu, as well as their respective security advisers. Foremost among those issues will be the Iranian nuclear program.It seems hardly a coincidence that Obama timed his visit for the start of spring. Netanyahu warned last year at the United Nations that by the spring or summer of 2013, Tehran would have acquired enough enriched uranium to build its first nuclear weapon.Click here for full JPost coverage of Obama's visit to Israel Four rounds of talks between the P5+1 nations and Iran have ended in failure, and allowed the Iranians to play for time. Worse yet, during the last round of talks, in Kazakhstan last month, the international community dropped two key demands: that Iran dismantle its subterranean enrichment facility at Fordow, and that it send abroad its 6.5 tons of low-enriched uranium.Economic and oil sanctions are severely hurting the Iranian economy, but so far, they have failed to convince Iran to freeze its nuclear program.Additionally Iran has denied the IAEA any access to its secret military site in Parchin, where the IAEA suspects that a nuclear trigger is being developed.Has Obama arrived in Israel to dissuade Netanyahu from unilaterally striking Iran’s nuclear sites? Quite possibly. That goal may only be achievable, however, if Obama privately tells Netanyahu what America’s red line on Iran is.If the red line is significantly behind Israel’s, Netanyahu may conclude that he cannot betray the ethos at the heart of the country’s defense doctrine, which holds that the Jewish people’s fate cannot ever again depend on other powers – even the most important of allies.If, however, Obama’s red line is close to Israel’s, Netanyahu may choose to stand down and let America complete its experiment to see if sanctions might change the minds of Iran’s rulers, before the US resorts to military action.Hence, the exchanges Obama and Netanyahu hold during this visit may be vital in deciding whether Israel goes it alone, or hands the keys over to the US.The escalating situation in Syria will furnish another urgent topic for discussion. In recent days, unconfirmed reports surfaced of a chemical weapon attack near Aleppo, Syrian jets bombed rebel positions in Lebanon for the first time since the civil war broke out, and UN peacekeepers were kidnapped (and later released) by radical Syrian rebels who have taken control of the area near the border with Israel.Syria has become a proxy battleground between Shi’ite Iran and its Sunni rivals. Iran is keeping the Assad regime alive through weapon and money transfers, and sending thousands of Lebanese Shi’ite Hezbollah fighters over the border to fight the rebels, while the Sunni Gulf states are financing and arming the rebels. This could destabilize Lebanon and its delicate sectarian balance.In light of the developing tinderbox, Israel will be looking to the US for support and coordination in containing the Syrian chaos. Containment contingencies, such as responding to chemical weapons attacks, or attempts to send advanced arms to Hezbollah, will form a crucial aspect of talks between Obama and Netanyahu, though much groundwork has been laid on this already.The two leaders can be expected also to discuss ways of kick-starting the peace process between Israel and the Palestinian Authority, and how to strengthen Fatah in Ramallah at the expense of Hamas in Gaza.During his September address to the General Assembly, Netanyahu set back the deadline on when Iran would cross an Israeli red line, but now, with Iran in possession of just under 170 kilograms of uranium enriched to 20 percent (according to the IAEA), time may once again be of the essence.Tehran would only need another 60 kg. to 90 kg. of medium-enriched uranium, which it could then quickly enrich further, to produce weapons-grade material, if the Islamic Republic’s Supreme Leader Ayatollah Ali Khamenei gives the order.The fact that new-generation centrifuges, which enrich uranium three to five times faster than the older centrifuges, have been installed at the Natanz site cannot be ignored, either.