The deadly explosion of pagers and walkie-talkies across Lebanon this week dealt another blow to President Joe Biden’s beleaguered efforts to reduce tensions in the Middle East, even as his top diplomats were present in the region reciting calls for calm.

       The absence of a full-blown war between Israel and Hezbollah has been touted by U.S. officials as a core achievement of the past 11 months amid failures to broker a cease-fire between Israel and Hamas, and halt the enormous civilian death toll and restrictions on humanitarian aid in the war-ravaged Gaza Strip.