WASHINGTON – The United States intelligence and defense communities are preparing a long list of possible military targets in Syria for President Barack Obama belonging to the Islamic State, a terrorist organization holding ground throughout eastern Syria and northern Iraq.The US government has stepped up its efforts to increase its knowledge of Islamic State activities and assets in and around Raqqa, the group’s nominal capital, after it finished taking over the region from the Assad government last week.The US understanding of the reality in the portion of Syria under Islamic State control – what the intelligence community calls “visibility” – has been poor, as evidenced most publicly by a covert rescue operation in July that incorrectly identified the whereabouts of several Americans held captive by the group.Islamic State has killed thousands of Christians and Muslims in the way of its march throughout Iraq, down the Euphrates and up the Tigris rivers, in an effort to form a caliphate that will extend from Baghdad to Tel Aviv.The US lists the group as a terrorist organization, but its public beheading last week of James Foley, an American journalist, shook Washington and prompted Defense Secretary Chuck Hagel and Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey to call the group “beyond anything we’ve ever seen.”Obama, too, called the group a “cancer” that poses a direct threat to the Muslims of Iraq, to US allies in Europe and to the American homeland."America does not forget," Obama said on Tuesday. "Our reach is long. We are patient. Justice will be done."State Department spokeswoman Jen Psaki repeated on Tuesday that, despite sharing a common enemy in the Islamic State, the US would not coordinate with President Bashar Assad should it choose to strike within Syrian territory. “Certainly we would not view it as being on the same side just because there is a common enemy,” she said. The US has repeatedly called for Assad to step down, and in recent days has blamed him for creating conditions that have allowed Islamic State to metastasize.“When it comes to the interests of the American people, the interests of the United States, we’re not going to ask for permission from the Syrian regime,” Psaki continued, adding, “We would obviously have a legal justification for any action taken.”Psaki said the political justification for striking Islamic State would be the protection of American lives. The threat is not restricted to borders, and thus US military options would not adhere to such restrictions, she said.Nearly a year ago, Obama weighed striking Syria after Assad used sarin gas against a civilian town, killing 1,400 people.Some 500 were children, and it was the deadliest attack in the three-year-old civil war to date.During that debate, Obama took a consequential walk through the White House grounds with his chief of staff, Dennis McDonough, to discuss how to proceed. The president decided on that walk to seek authorization from Congress to use force, prompting a dramatic flurry of activity on Capitol Hill, rare during the August summer recess. Obama took a similar walk on Monday with McDonough through those same grounds, though the White House did not provide a readout of the conversation. On Capitol Hill, no such flurry has matched what occurred last year. Administration officials have not said whether the president would, once again, request authorization for the use of force from Congress.