Liu Ye's SGZ biography with reference to Fu Zi wrote:孙权遣使求降，帝以问晔。晔对曰：“权无故求降，必内有急。权前袭杀关羽，取荆州四郡，备怒，必大兴师伐之。外有强寇，众心不安，又恐中国承其衅而伐之，故委地求降，一以卻中国之兵，二则假中国之援，以强其众而疑敌人。权善用兵，见策知变，其计必出於此。今天下三分，中国十有其八。吴、蜀各保一州，阻山依水，有急相救，此小国之利也。今还自相攻，天亡之也。宜大兴师，径渡江袭其内。蜀攻其外，我袭其内，吴之亡不出旬月矣。吴亡则蜀孤。若割吴半，蜀固不能久存，况蜀得其外，我得其内乎！”帝曰：“人称臣降而伐之，疑天下欲来者心，必以为惧，其殆不可！孤何不且受吴降，而袭蜀之后乎？”对曰：“蜀远吴近，又闻中国伐之，便还军，不能止也。今备已怒，故兴兵击吴，闻我伐吴，知吴必亡，必喜而进与我争割吴地，必不改计抑怒救吴，必然之势也。”帝不听，遂受吴降，即拜权为吴王。
This translates to:
Sun Quan sent a messanger begging to surrender and the Emperor (Cao Pi) asked Liu Ye for his opinion.
Liu Ye said,
"Sun Quan begs for surrender with no clear reason and it is likely that he maybe having an internal crisis. Not long ago, Sun Quan launched a sneak attack against Guan Yu and managed to accquire the four prefectures of Jing province. That made Liu Bei extremely furious and he was likely to launched a massive punitive expedition against Wu. Faced with strong external opponents, the masses in Wu would be unsettled. They were scared of Zhong Guo (refering to Wei) taking the opportunity to attack them and thus they are now begging to surrender. By doing so, they will be ensure that we will not send our armies against them and also, they will strengthen themselves by claiming that they have the support of our armies and thus confusing the enemies. Sun Quan is well-versed with military matters and he knows how to adapt and change his strategies. Hence, he is the person who is most likely to come up with this scheme. Right now, the world is divided into three portions. Wei occupies eight out of ten of China while Wu and Shu occupy one province each, each having geographical advantages like mountains and rivers, and both can aid each other in times of needs. This is the advantage share by these small countries. However, right now, these two countries are at war with each other and Heaven spells doom for them. Hence, we should launch an expedition and cross the river to attack Wu from the inside. With Shu attacking the outside and we attacking the inside, it will not take more than a month or so to bring an end to Wu. With Wu gone, Shu will then be alone. Even if we allow Shu to occupy half of Wu's territory (in the aftermath), Shu will still not be able to survive. Furtheremore, Shu only gain the external part of Wu while we gain the internal regions!"
Cao Pi replied,
"When others have the intention to surrender and we attack them, it will bring fear to those who have intention to join Wei. This cannot be done! Why don't I accept Wu's surrender and launch a sneak attack at Shu's rear?"
Liu Ye replied,
"Shu is far and Wu is near, if Shu hears that we are going to attack them, they will retreat and there is nothing we can do to stop them. At this moment, Liu Bei is very angry and he attacks Wu. If he knows that we are going to attack Wu, he will be delighted and will advance his troops to compete with us for Wu's lands. Liu Bei will surely not change his plan and turn around to help Wu instead. This is surely the way how things will go. "
Cao Pi refused to listen and he accepted Wu's surrender. He even awarded Sun Quan the title of King of Wu.
Going by this exchange, what do you think would have happened if Cao Pi listened to Liu Ye's advice and refuse to accept Wu's surrender? Would everything that Liu Ye say came true? Cao Pi was not a stupid man so what made him stuck to his own opinion?