It was a timely reminder that four years of relative calm on the Israeli-Lebanese border cannot be taken for granted. The Israeli military was focusing on Monday's rocket attacks on its Red Sea resort of Eilat and the neighboring Jordanian city of Aqaba and on increasing tit-for-tat attacks on its border with Gaza. But it was its border with Lebanon that was to prove the most deadly. An Israeli officer and several Lebanese soldiers were killed in the exchange of fire Tuesday across the volatile boundary. What would be considered gardening elsewhere in the world led to deaths and accusations from both Israel and Lebanon that the other violated U.N. Security Council Resolution 1701, the resolution which was intended to resolve the 2006 Israel-Hezbollah war. The U.N. peacekeepers in Southern Lebanon, UNIFIL, have since agreed with Israel that its engineers trimming a tree to ensure line of sight across the border were on the Israeli side of the Blue Line. Looking at the bigger picture though, is this the "grave escalation" Israel calls it, or is it a one-off reminder that tensions can and will flare up on this tense border.Experts and politicians alike highlight the fact these clashes were between the Israeli army and the Lebanese army only and not between Israel and its 2006 enemy Hezbollah. Paul Salem, director of Carnegie Middle East in Beirut, told CNN: "Hezbollah do not want a war, and they realized that if they got directly involved that would escalate things dramatically".Israeli experts agree if Hezbollah had got directly involved, the Israeli response would have been far more aggressive and the U.N. and U.S. calls for calm would have been easier to ignore.