Since the war began, there has been fear in Washington that other Arab nations, particularly Iran, would join Hamas in their war on Israel. Iran sponsors Hezbollah, which operates in Lebanon near Israel's northern border. Skirmishes have already occurred, raising concerns about an all-out war. Iran's foreign minister has made ominous statements, hinting at the possibility of the conflict spreading. The U.S. has taken these threats seriously and issued warnings to Iran through intermediaries. They have also deployed additional military forces as a show of force. Israel has reinforced its border and evacuated civilians in response. President Biden's message to Iran was clear: don't cross the border or escalate the war.