CAIRO (AP) — The former top U.S. commander in northern Iraq defended the multibillion dollar American effort to train Iraqi security forces despite this week’s Sunni insurgent offensive that has seen key cities occupied as soldiers and police abandoned their posts.

Mark Hertling, a retired general who led American forces in the volatile region in 2007-2008 as they fought to end sectarian warfare that pushed the country to the brink of civil war, said neglect by the Shiite-led government left Iraq in a precarious position and “squandered” the opportunity for real progress.