According to recent research, at least some of the most promising tungsten alloys that have been considered as replacement for depleted uranium in penetrator ammunitions, such as tungsten-cobalt or tungsten-nickel-cobalt alloys, also possess extreme carcinogenic properties, which by far exceed those (confirmed or suspected) of depleted uranium itself: 100% of rats implanted with a pellet of such alloys developed lethal rhabdomyosarcoma within a few weeks.

Depleted uranium is favored for the penetrator because it is self-sharpening and pyrophoric. On impact with a hard target, such as an armored vehicle, the nose of the rod fractures in such a way that it remains sharp. The impact and subsequent release of heat energy causes it to disintegrate to dust and burn when it reaches air because of its pyrophoric properties. When a DU penetrator reaches the interior of an armored vehicle, it catches fire, often igniting ammunition and fuel, killing the crew, and possibly causing the vehicle to explode.

In war, the advantages of Depleted Uranium munitions help the United States stomp other countries into the ground.

The United States and its NATO allies maintain that Depleted Uranium dust (a by-product) doesn't cause cancer and birth defects, however, 136 countries are citing other research saying that it does.

Which side do you think is right?

Here is the wikipedia entry:
en.wikipedia.org/wiki/Depleted_uranium