Israel and Hezbollah last fought on the ground in 2006, when Hezbollah terrorists crossed the border into Israel, abducting and killing several IDF soldiers. The ground confrontation lasted 34 days, resulting in the deaths of over 100 Israeli soldiers and 1,000 Lebanese civilians.

The main questions now are how much the conflict will escalate and whether the United States will get more directly involved in the defense of Israel.

Hamas conflict has pulled in an ever-widening web of countries and militias, from Lebanon to Iran. The prospect of a war in the Middle East raises one key question. Which country is on whose side?

Iran late on Tuesday fired ballistic missiles targeting two military bases of Israel and the headquarters of Mossad, Israel's intelligence service, claimed Iranian state television, citing Mohammad Bagheri,