The flashback right before John's death was completely missing in most European versions but some of it, until right before the kiss, was still in the first US version. In the new DVD releases the scene is now complete, making it the version Leone preferred.
Thanks to the complete version another characterisation of John Malleoy has become possible, as mentioned in a documentary included in some of the DVD versions. Events which led Malloy to Mexico can have their origins in a rivalry between Sean and John which is even likely to have made John a traitor.

German TV version from 2005 (Old European Version): 146:28 minutes
New DVD version: 150:30 minutes

0:00
The Mao quote at the beginning is missing:
The revolution is not a social dinner, a literary event, a drawing or a embroidary; It cannot be done with elegancy and courtesy. The revolution is an act of violence.
Mao Tse-Tung
40 seconds

143:41
The flashback right before John's death is missing, as well. Again, we see him in a seemingly happy situation back in Ireland. He, his friend Sean and a girl are running around happily. Then, John kisses the girl effusively. When he stops she turns to Sean, obviously happier to kiss him now. John is ignored while his smile slowly disappears.
197 seconds