BAGHDAD, March 19 (Reuters) - Only 18 percent of Iraqis have confidence in U.S.-led forces and most think the presence of foreign forces is making security worse, but despite that only about a third want them to leave now, a poll showed on Monday. The poll of more than 2,000 people, commissioned by the BBC, ABC News, ARD and USA Today, indicated Iraqis have become less optimistic about the future compared to a similar survey in 2005 when respondents were generally hopeful, the BBC said. Asked whether their lives were overall better or worse than before the invasion, 43 percent said better, 36 percent worse and the rest about the same. Expectations for how things will be in a year were much lower than in 2005, with only 35 percent expecting improvement compared to 64 percent in a 2005 survey. The survey showed sharp geographical variations, with confidence in U.S.-led forces highest in the north, at 46 percent, and non-existent in Baghdad, where 100 percent said they had not very much or no confidence in U.S.-led forces. Overall, 18 percent of Iraqis expressed confidence in U.S. forces and 69 percent said their presence made security worse. In Baghdad, the epicentre of violence, 100 percent said U.S. and other foreign forces had done a bad job in Iraq, opposed the presence of U.S.-led forces and said the presence of U.S. forces was making security in the country worse. Despite that, only 35 percent of all Iraqis and 36 percent in Baghdad said U.S. forces should leave now. The most popular view on how long they should stay was "until security is restored", with 45 percent of Baghdad residents and 38 percent of all Iraqis picking that option. SHARP VARIATIONS The survey also showed a sharp variation in opinions between Shi'ites and Sunni Arabs. Three in five Shi'ites said their lives were better now than before the invasion, while only 8 percent of Sunnis said the same. Post-war elections brought long-oppressed Shi'ites and Kurds to power and left many in the once dominant Sunni Arab minority feeling marginalised. That division was illustrated in attitudes to Iraq's Shi'ite-dominated security forces, with 80 percent or more of Shi'ites having confidence in the police and army, but only one in four Sunnis expressing any confidence. Among all Iraqis, the national unity government of Shi'ite Islamist Prime Minister Nuri al-Maliki inspired confidence in 49 percent, but that broke down into 72 percent of Shi'ites and just eight percent of Sunni Arabs. Despite their pessimism, 47 percent of Iraqis still said it was somewhat or absolutely right for the U.S.-led forces to invade Iraq. But again respondents were divided on sectarian grounds, with 70 percent of Shi'ites in favour and only two percent of Sunni Arabs expressing any support for the war. Asked whether Iraq was involved in a civil war, 42 percent of Iraqis said it was, but only one in four Shi'ites said yes compared to 63 percent of Sunni Arabs. About 86 percent were concerned about someone in their household being a victim of violence. Iraqis were also disappointed by reconstruction efforts since the invasion, with 67 percent saying efforts had not been effective. The majority of Iraqis said they thought Syria (66 percent), Iran (71 percent) and Saudi Arabia (56 percent) were actively engaged in encouraging sectarian violence.