Private equity firms are facing stiffer competition in Southeast Asia as geopolitical tensions, including the US-China trade war, have prompted peers to look for investment targets outside the mainland and developed markets in Asia, according to Warburg Pincus.“Investors have kind of woken up to the opportunities in Southeast Asia, in particular Vietnam,” Jeffrey Perlman, a Warburg Pincus managing director and head of Southeast Asia, said in an interview. The region has been a “significant…