Former US Army Lieutenant Colonel Daniel Davis wrote an article for defense website 19fortyfive detailing how Ukraine's joining NATO could spark a war with Russia.

Davis wrote in the article that instead of trying to call Russian President Vladimir Putin's bluff on Ukraine and offering Ukraine and Georgia NATO membership, there is another way that the US and NATO could set about to do things, as such an action would compel Putin to act to protect Russian security interests.

There are more practical measures that Washington can use, he writes, that would deescalate the situation and increase US national security. 

While the US's usual reflex would be to show strength against Russia, using either the threat of sanctions or military posturing near the Russian border, along with military exercises and talk of expanding NATO to Russia's border.

However, a history of failed military-first policy shows that such a time is beyond us, and new methods can be applied today.

Specifically, Davis points out three things the US can do to deescalate the situation with Russia.

First, NATO's standards specifically state that no nations can be invited to join the alliance “which have ethnic disputes or external territorial disputes, including irredentist claims, or internal jurisdictional disputes," according to NATO's own documents. Ukraine has ethnic disputes between its eastern and western parts, Davis says, and has major territorial disputes with Russia. 

Second, there is no value for the US in risking war with Russia or in escalating tension with it over Ukraine.

Third, and more importantly, the best chance of deescalating the situation and preventing war would be for Ukraine to declare military neutrality, thus making it so that it will not join any alliance, and reduce Putin's motivation to invade it.

Putin would be willing to go over Ukraine to protect its border, just as it did with Georgia in 2008. However, such an endeavour would have no value for the US.