text:  How concerned is the U.S. that this full-scale war could break out, and is there anything more that American officials can do to avoid that? Well, again, they're going the diplomatic track, but ever since the Hamas attack on Israel back in October, the U.S. has been extremely concerned about the Israeli-Hamas war expanding. The U.S. is also worried that any Israeli invasion of Lebanon could trigger a sharp response from Iran against Israel,