US arms Israel with multi-billion dollar weapons like fighter jets, iron dome, jdams etc. Iran is supplying Hamas, Hezbollah and Houthis with low level weaponry like unguided rockets, RPGs, anti-tank weapons, drones etc Iran's way of fighting wars post-islamic revolution has always been through attrition. Use cheap speedboats to harass battleships, use cheap chinese drones to overwhelm radar systems, use IEDs and anti-tank mines to destroy enemy armor. Iran can fund dozens of such organization when all you need to do is supply low level weaponry. Besides, Palestinians get billions in aid from rich middle eastern countries, diaspora Palestinians, muslim charities and even the west, in the absence of investing all that money on their population, all they do is buy weapons. On a side note, the combined wealth of Hamas' leadership is said to be north of $15 billion! One can only imagine what pile of cash Palestinian Authority is sitting on.