Historian Niall Ferguson warns that Putin could resort to weapons of mass destruction if Russia loses in eastern Ukraine.

• If Russian President Vladimir Putin fails to achieve a "conventional forces victory" in eastern Ukraine, he may use weapons of mass destruction, including chemical and tactical nuclear weapons, according to Niall Ferguson, a senior fellow at the Hoover Institution at Stanford University.
• The Biden administration appears to be dismissing the serious risks too lightly, according to what he said on CNBC's "Squawk Box Asia" on Thursday.
• Ferguson believes that the U.S. strategy of allowing the war to continue and hoping for a regime change in Moscow is a "very hazardous" approach.

If Russian President Vladimir Putin fails to achieve a "conventional forces victory" in eastern Ukraine, he may use weapons of mass destruction, including chemical and tactical nuclear weapons, according to Niall Ferguson, a senior fellow at the Hoover Institution at Stanford University.

Ferguson, a history professor at Harvard University, stated on CNBC's "Squawk Box Asia" that the Biden administration appears to be dismissing serious risks too lightly.

Ferguson believes that the U.S. strategy of allowing the war to continue and hoping for a regime change in Moscow is a "very hazardous" approach.

In recent days, Russian troops have retreated from regions near Kyiv, with the aim of completely liberating the Donbas region, as stated by Sergei Rudskoy, Russia's Armed Forces deputy chief of staff.

Since Russia illegally annexed Crimea in 2014, the Donbas region in eastern Ukraine has been the site of conflict between Ukrainian forces and Moscow-backed separatists.

If it becomes clear that Russian forces are unable to achieve a decisive victory in Donbas, Putin may face a difficult situation without a clear exit strategy.

Putin has demonstrated a willingness to cause "horrific destruction" with conventional weapons, including cruise missiles. Russia possesses the largest nuclear arsenal globally, with the U.S. following closely behind.

According to Phillips O'Brien of the University of St. Andrews, it is unlikely, if not impossible, for Putin to use WMDs.

The use of WMDs could increase international support for Ukraine, including weapons and sanctions against Russia, but it is unclear how such weapons would aid Russia in achieving its political goals, according to O'Brien.

"How does killing people in cities aid in winning the war?" he questioned.

Moscow may not succeed in capturing and maintaining control over the south and east of Ukraine, according to O'Brien.

Putin's objective is not solely the annexation of Ukraine, but rather to prevent its successful transition into a Western-oriented democracy, according to Ferguson.

Western response

If Putin escalates with nuclear or chemical weapons, policymakers in Washington and Europe will face a huge dilemma, according to Ferguson, who believes it is really quite likely.

He stated that they have two "terrible" options to choose from.

He stated that continuing to provide conventional weapons after a nuclear weapon has been used or taking military action and risking an escalation are the only two options.

Ferguson stated that the main issue with strategy is when one consistently claims they won't use military force, it can lead the other side to believe they will always retreat, thus prompting an escalation.

G-7 foreign ministers cautioned against employing chemical, biological, or nuclear weapons on Thursday.

The utilization of such a weapon by Russia would be unacceptable and lead to severe consequences, as stated by ministers.

Ferguson stated that the situation with heavily armed nuclear powers on the brink of conflict and Russia's declaration of war against the West is much more dangerous than most people realize.

Although Ferguson believes we're not on the brink of World War III, he admits we can't completely rule out that possibility.