This bill increases U.S. funding for joint defense cooperation with Israel on anti-tunnel technology and capabilities. Specifically, it raises the annual spending cap for United States-Israel anti-tunnel cooperation from $50 million to $80 million, an increase of $30 million per year. The legislation is motivated by the discovery of extensive tunnel networks used by Hamas, Hezbollah, and other terrorist organizations in Gaza and Lebanon, as well as recognition that the United States faces similar underground threats at its southern border and in other regions. The expanded funding is intended to accelerate technology sharing and joint development efforts between the two countries that could benefit both nations and their allies in detecting, mapping, and countering subterranean terror infrastructure. The bill modifies an existing authorization from 2016 and does not specify a sunset date, meaning the increased funding level would continue unless Congress changes it in future legislation.