A return to pre-1967 borders would not necesarily the best way to achieve peace.The situation is so complicated that one simple solution would not be enough to really have peace.The best way to have peace is to have powerful countries like the United States be more proactive and offer proactive solutions.
Returning Israel to the pre-1967 borders is not the best way to achieve peace. This would create much more strife between Israel and Palestine. It may possibly incite war. Additionally, some of the borders would be so small that it would be too difficult to defend a territory, thus leading to more conflict.