Some of Israel’s decisions in its war against Hamas – including cutting off food and water for Gaza – could “harden Palestinian attitudes for generations” and weaken international support for Israel, Barack Obama said on Monday. In rare comments on an active foreign policy crisis, the ex-US president said any Israeli military strategy that ignores the human costs of the war “could ultimately backfire”. “The Israeli government’s decision to cut off food, water and electricity to a captive civilian population [in Gaza] threatens not only to worsen a growing humanitarian crisis – it could further harden Palestinian attitudes for generations, erode global support for Israel, play into the hands of Israel’s enemies, and undermine long-term efforts to achieve peace and stability in the region,” said Obama. Israel has heavily bombarded Gaza with airstrikes since Hamas’s 7 October attack on Israel left more than 1,400 people dead. Israel’s strikes have killed more than 5,000 Palestinians, Gaza officials say. Obama condemned Hamas’s attack and reiterated his support for Israel’s right to defend itself. But he cautioned about risks to civilians in such wars. It was not clear whether Obama had coordinated his statement with Joe Biden, who is running for a second term as US president next year. Biden was Obama’s vice-president for eight years after they won the 2008 election. During his presidency, Obama often backed Israel’s right to self-defense at the start of conflicts with Hamas in Gaza. But he quickly called for Israeli restraint once Palestinian casualties mounted from airstrikes. Gaza, a 25-mile strip of land that is home to 2.3 million people, has been ruled politically since 2007 by Hamas, an Iran-backed Islamist group. But it faces a blockade from Israel. The Obama administration sought – but ultimately failed to broker – a peace deal in negotiations between Israel and the Palestinians. Since taking office in early 2021, Biden has not tried to resume long-stalled talks, saying that leaders on both sides were too intransigent and the climate was not right. Obama and the Israeli prime minister, Benjamin Netanyahu, had a testy relationship when Obama was in office, including when Obama’s administration was negotiating a nuclear deal with Iran. Biden, as Obama’s vice-president, often acted as a mediator between the two men. In his statement on Monday, Obama acknowledged that the US had itself “fallen short of our higher values when engaged in war”, especially after the September 11 terrorist attacks in 2001.