Turkey has received the expected lukewarm support from its NATO allies over the downing of one of its jets by Syrian troops but has warned Syria it is boosting its defenses. NATO's limited backing comes in part because Turkey admits that its aging Phantom air force jet may momentarily have strayed into Syrian airspace, but also because NATO simply does not wish to, and arguably politically and militarily could not, become involved in a Libyan-style air campaign. The Syrian regime was quick to issue its side of the story and also to say that it was mounting an air sea rescue operation to look for the crew of the downed aircraft. This, it said, had come down inside Syria's territorial waters. The Turks also announced that they were mounting a search, but since they maintained the Phantom was in international airspace when it was hit, their search area was different from that of the Syrians. Nevertheless it appears that another Turkish jet, this time seemingly involved in the search and rescue operation, entered Syrian airspace and was itself fired on, this time without being shot down. Some sources have described the original Phantom as being equipped as a reconnaissance aircraft. If this is true, it is highly unlikely that its final flight was actually the first time that it or similar Turkish surveillance planes had flown close to or actually into Syrian airspace. For whatever reasons, the Turkish military will want to know as much as possible about what the Syrian armed forces are doing. The destruction of the Turkish jet and the loss of its two crew has added to the anger that Turks already feel at the brutal repression being carried out by the Assad regime. Yet in a dignified interview, the father of the pilot said yesterday that he did not want the death of his son to be the cause of war. Nevertheless Premier Recep Tayyip Erdogan yesterday announced that the rules of engagement for Turkish troops have been changed and that any Syrian troops approaching the border will be considered as “a threat". This could pose challenges for the Syrian army seeking to chase elements of the Free Syrian Army back into Turkey. It cannot be imagined that the Syrian regime would wish to commit its forces to a fight with the large and tough Turkish troops, as well as having to grapple with the still-growing rebellion.Indeed if Syria wished to provoke Turkey there is a far easier button to push. By a treaty anomaly, almost a century old, a small detachment of Turkish troops still guards the tomb of an Ottoman Sultan, 25 kilometers inside Syria. The shrine is housed in a small hilltop fort near the village of Karakozak. Ironically the location is now an island connected to the mainland by a causeway, because it sits in the middle of the man-made Lake Assad. Interdicting the resupply or changeover of these men would not be taken lightly in Ankara.