Can't you fall in love and not have a possessive relationship? I love someone and she loves me and we get married - that is all perfectly straightforward and simple, in that there is no conflict at all.
I think that many of the mobilizations against the wars waged by the US and its allies since 2001 have been non-violent and massive. We have seen them throughout European capitals and in the US, and in many other parts of the world as well. So it is not only imaginable, but already actual.