The Egyptian people woke up two Saturdays ago to the sad news of the crash of a Russian plane flying 224 people from Sharm El-Sheihk to St Petersburg at the end of their vacations in the Sinai resort. Initially, most people took it for granted that the probable cause of the crash was either engine failure or poor maintenance. No one thought of any external cause that could have brought the plane down in Sinai. However, speculation about other causes started piling up from unnamed security sources in the West, insinuating that the Russian plane crashed because of terrorism. In the meantime, the Islamic State (IS) group tweeted that it had carried out the attack against the civilian plane but declined to say how. Coming just three or four days after the tragic incident, the worst in the history of Russian civil aviation, no one took the claim seriously. In fact, senior officials saw the tweet as an attempt by the terrorist organisation to damage the tourism sector in Egypt. But Egyptians were in for another unpleasant surprise. The day President Abdel-Fattah Al-Sisi began his first official visit to the United Kingdom, on 4 November, the British government announced that it had started an evacuation plan for the 20,000 British tourists vacationing in Sharm El-Sheihk. While the Egyptian president was still paying an official visit to Great Britain, British Prime Minister David Cameron told reporters that it was “more likely than not that . . . a terrorist bomb” caused the crash. On the other side of the Atlantic, US President Barack Obama said that Washington was “seriously” considering the possibility of a bomb having been aboard the plane. And when the US president, as well as the British prime minister, began talking about a bomb on the Russian plane, Moscow acted as if the plane came down because of a terrorist attack. Following a phone call with Cameron, Russian President Vladimir Putin ordered, on 6 November, the evacuation of all Russian tourists in Egypt. He even went further than other governments by halting flights all to Egypt — even to Cairo. In the meantime, and in order to soften the blow to Egypt, Kremlin spokesman Dimitry Peskov told news agencies on the same day that the Russian decision did not mean that Moscow believed the crash was due to an attack. It is interesting to note that while President Obama said that the United States was seriously considering a bomb as a probable cause behind the crash, the White House spokesman, Josh Earnest, told reporters in a press briefing on 5 November that the United States had not made “our own determination about the cause of the incident.” He added, “We can't rule anything out, including the possibility of terrorist involvement.” On Saturday, 7 November, the lead Egyptian investigator presiding over the mission investigating the crash held a press conference in which he stressed that no cause had been determined to explain why the Russian plane crashed. Two days earlier, some media in the West published stories about American intelligence sources in the Middle East intercepting messages about the crash between IS elements in Raqqa, their capital in Syria, and terrorists in Sinai. Other sources talked about IS terrorists celebrating the “downing “ of the Russian plane. In the original IS tweet, the group said that it caused the crash in retaliation for Russian air strikes against its targets and positions in Syria. If this is true, and I tend to believe that the Russian plane crashed because of a terrorist attack, then the terrorist act on the part of IS against the plane means that the war in Syria against IS has spilled over to Sinai, Egypt. In other words, both Egypt and Russia are now fighting the same enemy in a common war. Previously, Egypt has been battling terrorists affiliated with IS in the Sinai desert, while Russia was targeting the positions of this organisation from 30 September — each country waging its war seperately. The situation, from a strategic point of view, has changed with the “downing” of the plane. The fight should become a joint effort between Cairo and Moscow, notwithstanding the fact that Egypt is supposedly a partner in the US-led international coalition to degrade and defeat IS. Was the downing of the Russian plane over Sinai a message to Cairo that supporting Russian air strikes in Syria would have a serious economic and political cost to Egypt's security and economy? For my part, I do not rule this out. Strategic dynamics are changing in the Middle East, and they are changing fast and dangerously. Maybe Egypt needs to rethink its strategic priorities now that an undeclared war — this time, targetting Egypt's economy — has started, coupled with a fierce media campaign to “punish” Egypt for its independent strategic directions. Egypt is today waging a war on three fronts: one in Sinai, the second along its western borders with Libya, and the third in Syria. If it is proven that IS is responsible for the downing of the Russian plane then we have no option but to re-establish diplomatic relations with Syria and join the Russian-Syrian military operations against IS in Syria. If we want to protect our survival as a nation, there can be no other option. The international coalition to “degrade and defeat” IS has failed us. The writer is a former assistant to the foreign minister.