You do know that every single one of these terms is defined at China's sole discretion, right? China "has always pursued..." is an observation, not an affirmation of the policy or a continued commitment to it. Even if taken at face value, when China develops a complete LoW system and fires its weapons as soon as it detects an enemy attack in progress, that's completely consonant with NFU.From the 2019 Defence White Paper:
"中国始终奉行在任何时候和任何情况下都不首先使用核武器、无条件不对无核武器国家和无核武器区使用或威胁使用核武器的核政策,主张最终全面禁止和彻底销毁核武器,不会与任何国家进行核军备竞赛,始终把自身核力量维持在国家安全需要的最低水平。中国坚持自卫防御核战略,目的是遏制他国对中国使用或威胁使用核武器,确保国家战略安全。"
Translation:
"China has always pursued the nuclear policy of no first use of nuclear weapons at any time and under any circumstances, and unconditionally not to use or threaten to use nuclear weapons against non-nuclear-weapon States or nuclear-weapon-free zones; it advocates the eventual complete prohibition and thorough destruction of nuclear weapons; it will not engage in a nuclear arms race with any country; and it has always maintained its nuclear forces at the minimum level required for national security. China adheres to a self-defense nuclear strategy aimed at deterring the use or threat of use of nuclear weapons by other countries against China and ensuring national strategic security."
The white paper says that Chinese nuclear forces will be maintained at the minimal level for national security, in order to deter others from using nuclear weapons against her.
Straight from the horses' mouth.
Another definition to pay close attention to is "non-nuclear weapon state" - what exactly does that mean? Is a state under a nuclear umbrella like Japan a nuclear weapons state or not?
"[China] will not engage in a nuclear arms race" is also another vacuous statement. What's an arms race? If China sprints toward parity with the US, is that an arms race? Not in China's telling; that's just it engaging in a completely reasonable build up to maintain its self defense.
We come to the most important phrase: "minimum level required for national security". What's that? Is it 350 warheads? 500? 5000? The answer is "minimum level" is exactly what China says it is. If China decides that "minimum level" means parity with the US then that's what it means.
If this document was ever written in good faith then those days are past. It still serves a useful diplomatic function in gaslighting people about China's nuclear expansion, but we should be shrewder than that. Ultimately, this policy should be viewed as something like