By Yimou Lee and Ben Blanchard TAIPEI (Reuters) – Taiwan goes to the polls on Saturday to elect a new president and parliament under the shadow of an increasingly assertive China which has called the vote a choice between “peace and war”. But no matter who wins the elections, Beijing’s military and economic pressure on Taiwan could continue and may even increase, say Taiwan security officials. China claims Taiwan as its own territory despite strident objections from the government in Taipei and has never renounced the use of force to bring it under Beijing’s control. Besides its territorial si…