Non-violence, compassion and loving the enemy are central to the Buddhist way of life - especially in Tibetan Buddhism. How could he, with the eyes of the world upon him, honestly advocate any form of violent path against China? And even if he did, what good would it serve?
Every time any publicity about Tibet has been generated the net result has always been more torture, more beatings, more disappearances.
The Tibetan people understand his message and it is not true that his stand is designed to appeal to his many Western admirers.
The dilemma facing the Dalai Lama revolves in part about the problem within Buddhism in general and of "being in the world but not of it". A problem the previous Dalai Lama spoke about often and which probably led in part to the invasion by China - ie neglect to implement political reforms. This problem also stems from having a religious leader running a country.
I think the comparisons with Gandhi are also flawed, mainly because Gandhi was not in the same sense a religious figure.