Let's break it down: "As formal diplomatic ties with the PRC (China)" this means 'In order to maintain a good relationship with China' "many countries have their own "One China Principle" " This means each country treats China and its territories with a certain level of respect to what China wants "enshrining the level of recognition that country affords the one China principle." This part means that the country's "One China Principle" is a signifier of how much that country is willing to cooperate with China in regards to China's territories. In short "enshrining the level of recognition" means formally declaring the extent to which the country agrees with or disagrees with China, in regards to that particular policy.

enshrining the level of recognition that country affords the one China principle. To enshrine is fancy way to say to honor. So here it is saying that a country honors China’s policy to a certain level. Honestly, it’s not really the best usage of “enshrining”. I think the author wanted to say “honoring” and simply substituted it with “enshrining”. But it doesn’t really work here. He is honored in history. He is enshrined in history. This works as this is using honor to mean “recognize with respect”. However, if you say, “I will honor the deal”, it means I will accept the deal and not go against it. This is what the author wants to say. But you cannot say “I will enshrine the deal”. It would read better and more clearly like this: honoring the level of recognition of the one China principal that country affords. Better to keep “level of recognition of the one China principal” together. To afford something means you can pay for it but not always with money. I can’t afford to be late. This means I can’t be late cause it would cost me time, hardship, grief, etc. So “the level that country affords” means the level the country is willing to pay (in social conscience, political repercussions, etc.). It’s amother way to say “that the country can accept”.