【文/观察者网专栏作者 周波】

核武器的重要性又一次不言而喻。俄总统普京发出的核打击重磅警告，让人们感觉到现在讨论核裁军完全是徒劳的。可以想见，朝鲜是如何在为自己已经发展了核武器而庆幸。人们不禁猜测，下一个可能出现在亚洲或者中东地区的拥核国家究竟是哪一个。

我们正在踏入一个核丛林，在那里，一枚枚核弹如低垂的果实，诱人地摇曳着。但是，如五个核大国在一月份的联合声明中所誓言的，“核战争不可能赢，也决不能打”，那么一个现实可行的方法是，五个核大国保证不首先对对方使用或威胁使用核武器。

这对所有核大国来说都是可能的，因为这不会影响到它们的有效威慑力。 自1964年引爆核装置以来，中国一直承诺在任何时候、任何情况下都“不首先使用”核武器。中国认为本国核战略和核政策是核大国中最为稳定、最为连贯且最可预测的。

美国总统拜登此前坚持，美国核武库的唯一目标是威慑，只在必要时才发动核攻击用于报复，该立场与“不首先使用”政策十分接近。不过上个月，美国国防部在其《核态势评估报告》中宣布，“只有在极端情况下才会考虑使用核武器，以捍卫美国或其盟友和伙伴的重要利益”，这与拜登之前的立场相比是一种倒退。

美国比任何其他国家都更有能力做出不首先使用核武器的承诺，因为它拥有压倒性的常规军力优势。人们很难找出一个美国无法用常规武器完成的任务。

在西太平洋地区，中国人民解放军和美军常规军力间的差距正在缩小，但很难想象在潜在的冲突中，美国不得不首先对中国发动核打击。

最关心美国核政策的是美国的盟友，他们担心失去美国核保护伞后本国的安全。但基辛格常说：“大国不会为了他们的盟友而自杀”。

美国的盟友倒也不必担心。由于对任何美国盟友的核打击几乎必然会招致毁灭性的核报复，对手首先发动核攻击的概率很小。如果美国能与朝鲜谈判达成“不首先使用核武器”协议，反而可能阻止平壤进一步发展核武器。

相互确保“不首先使用”可以作为北京和华盛顿之间建立战略稳定的第一步。据报道，五角大楼担心中国的核武库到2030年可能增加两倍，达到1000枚核弹头。

就算这是真的，中国的核武器数量同美国相比也很小。要想达到核均势，中国必须大幅增加其核武器数量，或者美国必须将其核武器数量减少到中国的水平。这两种情况都不可能发生。

真正的挑战是如何让俄罗斯参与进来。1982年6月，苏联领导人勃列日涅夫在联合国做出了“不首先使用核武器”的承诺，那是由于苏联在与北约对峙的欧洲战场上，对自身的常规军力优势充满了信心。随着1989年苏联解体后俄罗斯常规军力每况愈下，俄罗斯在1993年放弃了这一承诺。

如果俄罗斯认为其“先升级后降级”的战略阻止了美国派兵干预乌克兰，那么它需要三思。无论核武器看起来多有威慑力，美国也没有打赢越南、伊拉克或阿富汗战争。

核武器也没有帮助莫斯科降低乌克兰面对俄入侵时的强烈抵抗。相反，普京关于可能使用核武器的威胁，严重损害了俄罗斯的国家形象。在2018年的一部纪录片中，普京问道：“若没有了俄罗斯，还要世界干什么？”。可以反问一句：若没有这个世界，俄罗斯又会在哪里？

欧洲的安全取决于俄罗斯和北约是否能最终达成协议。美欧跨大西洋联盟可以单方面向俄罗斯承诺不首先使用核武器。俄罗斯比以往任何时候都更依赖核武器，但很难想象俄罗斯会对一个拥有30个成员国，其中还包括3个核国家的集团发动核打击。

2001年，中国和俄罗斯承诺互不首先使用核武器，也不将战略核导弹瞄准对方。如果中美之间能够达成类似的协议，那么美国、北约和俄罗斯之间达成协议将变得相对容易。

有一个值得借鉴的经验：1998年印度和巴基斯坦进行核试验后，中国和美国就两国核武器“互不瞄准”发表了一项联合声明，以示团结。这进一步促成五个核武器国家于2000年发表联合声明，宣布它们的核武器互不瞄准或不瞄准任何其它国家。

批评者可能会说，在未经核查的情况下互不瞄准仅有象征意义。但在核领域，如果这能使核大国对它国安全承担道义上的责任，那这种象征意义也是有用的。不首先使用核武器的承诺将是核裁军的巨大进步，它让人们相信，一个没有核武器的世界，无论多么遥远，终有一天会成为可能。

翻译：祖白地亚

核译：许馨匀 韩桦

Zhou Bo: World needs ‘no first use’ pledge by US, Nato and Russia to avoid nuclear war

Nuclear weapons look awfully important again. Given Russian President Vladimir Putin’s not-so-thinly veiled warning of a nuclear attack, it is a fool’s errand to talk about nuclear disarmament now. One can imagine that North Korea thinks it is fortunate to have developed nuclear weapons, and one can only guess which would-be nuclear state might crop up next in Asia and the Middle East.

We are stepping into a nuclear jungle where nukes are like low-hanging fruit swaying enticingly. But if “a nuclear war cannot be won and must never be fought”, as the five nuclear powers vowed in a joint statement in January, then one realistic step is that they pledge not to be the first to use or threaten to use nuclear weapons against each other.

This is possible for all nuclear powers as it won’t compromise their effective deterrence. Since it detonated a nuclear device in 1964, China has pledged a policy of “no first use” of nuclear weapons at any time and under any circumstances. It says its nuclear strategies and policies are the most stable, sustainable and predictable among the nuclear powers.

The US Department of Defence announced last month in its Nuclear Posture Review that it “would only consider the use of nuclear weapons in extreme circumstances to defend the vital interests of the United States or its allies and partners”. Such a view is a step back from US President Joe Biden’s previous position that the sole purpose of the US nuclear arsenal is deterring – and if necessary, retaliating against – a nuclear attack. Such a position is only a stone’s throw from a no first use policy.

The United States can afford to make a no first use commitment more than any other country because it has overwhelming conventional military superiority. One can hardly cite a mission the US could not accomplish with conventional weapons.

The gap between the conventional forces of the People’s Liberation Army and the US military is closing in the western Pacific, but it is difficult to imagine a potential conflict in which the US would have to launch a nuclear strike first against China.

The primary concern over America’s nuclear policy comes from US allies who are worried about their security without the American nuclear umbrella. “Great powers don’t commit suicide for their allies”, as Henry Kissinger is often quoted as saying.

They do not have to worry. Knowing a nuclear strike on any US ally will almost certainly invite a devastating nuclear retaliation, an adversary is unlikely to launch a nuclear strike first. If the US could negotiate a “no first use” agreement with North Korea, it might discourage Pyongyang from further developing nuclear weapons.

Mutual assurance on no first use can serve as the first step in establishing strategic stability between Beijing and Washington. The Pentagon reportedly worries that China could triple its nuclear arsenal to 1,000 nuclear warheads by 2030.

Even if this turns out to be true, China’s nuclear stockpile is still only a fraction of that of the US. To talk about nuclear equilibrium, China would have to drastically increase its number of nuclear weapons or the US would have to reduce its stockpile to China’s level. Neither is possible.

The real challenge is how to get Russia involved. In June 1982, Soviet leader Leonid Brezhnev made the no first use pledge at the United Nations because Moscow was confident about the advantages of its conventional military forces on the battlefield over Nato in Europe. As the Russian conventional military forces deteriorated after the collapse of the Soviet Union in 1989, Russia dropped its pledge in 1993.

If Russia believes its “escalate to de-escalate” strategy has deterred the US from sending troops to intervene in Ukraine, it needs to think again. No matter how formidable nuclear weapons seem, they did not help the US in Vietnam, Iraq or Afghanistan.

They have not helped Moscow in mitigating Ukraine’s strong resistance against Russia’s invasion, either. Instead, Putin’s threat on the possible use of nuclear weapons has severely tarnished the image of Russia. In a 2018 documentary, Putin asked, “why do we need a world without Russia in it?”. The better question is, where would Russia be without the world?

Security in Europe rests on whether Russia and Nato can eventually make a deal. The transatlantic alliance can afford to pledge no first use, even unilaterally, against a Russia which relies on nuclear weapons more than ever. It is hard to imagine why Russia would in any circumstances launch a nuclear strike against a grouping that has 30 member states, including three with nuclear weapons.

In 2001, China and Russia agreed not to be the first to use nuclear weapons against each other or target strategic nuclear missiles against each other. If a similar agreement could be made between China and the US, then reaching an agreement between the US, Nato and Russia would become easier.

Here is a good lesson to learn. In the wake of the nuclear tests by India and Pakistan in 1998, China and the US came to a joint declaration that they would not target each other with their nuclear weapons to demonstrate solidarity. This led to a joint statement among the five nuclear-weapon states in 2000 that their nuclear weapons are not targeted at each other or at any other states.

Critics might argue that de-targeting weapons without verification is only symbolic. But, in the nuclear arena, even symbolism is useful if it holds the nuclear powers morally responsible for the security of others. A pledge of no first use is a huge step forward in nuclear disarmament. It tells us a nuclear weapon-free world, however distant, is still possible one day.

Senior Colonel Zhou Bo (ret) is a senior fellow of the Centre for International Security and Strategy at Tsinghua University and a China Forum expert

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