The reluctance of Israel's Prime Minister, Benjamin Netanyahu, to respond positively to US President Joe Biden’s calls for a ceasefire to end the latest cycle of Israeli-Palestinian hostilities raises worrying questions about Mr Biden’s ability to maintain Washington’s traditional leadership role in the Middle East. Previously, when fighting erupts between Israel and Palestinians, it has been incumbent on Washington to broker a ceasefire to bring hostilities to an end and prevent further suffering for civilians. Yet, while Mr Biden has made repeated calls for such a ceasefire, Mr Netanyahu has resisted. Mr Biden’s efforts to end the fighting began soon after the commencement of hostilities. Following his first telephone call with Mr Netanyahu, he made the somewhat optimistic prediction that the fighting would end “sooner rather than later”. Since then, rather than heeding the ceasefire call, both sides have contributed to a marked escalation in fighting. Israeli warplanes launched a fresh wave of air strikes in Gaza at daybreak on Thursday, even though a senior Hamas official predicted a ceasefire might be possible within days. Humanitarian organisations say the significant proportion of fatalities caused by Israeli air strikes in Gaza are Palestinian civilians, including many children. In the past 10 days, an estimated 250 Palestinians have been killed in both Gaza and the West Bank, while 12 Israelis have lost their lives. The Hamas offer has prompted international mediators, including Egypt, Jordan and France, to intensify efforts to halt the bloodshed, with Egyptian President Egypt's President Abdel Fattah El Sisi stating that his country was "going to great lengths to reach a ceasefire... and hope still exists". France has also proposed a resolution with the UN Security Council, in coordination with Egypt and Jordan, calling for a ceasefire. French President Emmanuel Macron, together with President El Sisi, who is in Paris for summits on Africa, agreed on the resolution in a video conference with Jordan’s King Abdullah II earlier this week. But Mr Netanyahu continues to insist that he has no timeframe for ending Israel’s deadly assault on Gaza, and that military operations will only end when he is satisfied that sufficient damage has been inflicted on Hamas’s military capabilities, especially the network of underground tunnels in Gaza where its rocket manufacturing operations are understood to be stored. In remarks reported by Israeli media earlier this week following a closed question-and-answer session with foreign envoys to Israel, Mr Netanyahu was quoted as saying: "We're not standing with a stopwatch. We want to achieve the goals of the operation. Previous operations lasted a long time, so it is not possible to set a timeframe." Following his fourth conversation with the Israeli leader since the start of the fighting, Mr Biden said he expects a "significant" de-escalation in hostilities in Gaza. Even as US Middle East envoy Hady Amr met with Palestinian President Mahmoud Abbas, Mr Biden has faced increasing pressure from his own Democratic Party to do more. His difficulty in persuading Israel is particularly embarrassing given the frantic diplomatic effort that is underway elsewhere to bring the fighting to an end. The drive for a ceasefire, moreover, comes amid fears of the conflict extending beyond the confines of Gaza and the Israeli-occupied Palestinian territories, after Palestinian militants based in Lebanon were accused of firing rockets at Israel’s northern border. In many respects, Mr Biden has only himself to blame for the lack of influence he can bring to bear on the Israeli government. That is because of his previous neglect of the Israeli-Palestinian issue. Rather than continuing with the peace process initiated by the Trump administration, which resulted in the ground-breaking Abraham Accords between Israel and a number of Arab states, the Biden administration decided to make reviving the nuclear deal with Iran the centrepiece of its Middle East policy. Mr Biden has also been accused of delivering a diplomatic snub to Mr Netanyahu by making him wait for nearly a month before making his first phone call to the Israeli leader. Washington’s preference for dealing with Iran, moreover, has now backfired following reports that Hamas has relied heavily on Iran to build the arsenal of powerful rockets that are currently being fired at Israel on a daily basis. Mr Biden’s influence over Israel has also been compromised by deep divisions among Democrats over the policy they should adopt towards it. While the President takes the traditional Democrat position of supporting Israel, activists on the left have suggested imposing sanctions and depriving Israel of its $3.9 billion annual American aid package because of its human rights violations in Gaza. As a result, Mr Biden now finds his leadership credentials under close scrutiny, with his ability to arrange a ceasefire in Gaza proving to be the most important challenge of his presidency to date. <em>Con Coughlin is a defence and foreign affairs columnist for The National</em>