The US' expulsion of 60 Russian diplomats in response to a chemical attack on a former Russian spy in the UK, announced earlier this week, has a huge loophole.

A State Department official confirmed that the US will not require Russia to reduce the number of staff in its Washington embassy.

In other words, the 60 diplomats — many of whom were undercover intelligence officers — who were kicked out can be replaced by others.

Targeted expulsions like this week's are not uncommon; the Obama administration's move to expel 35 diplomats in 2016 was made under similar conditions.

President Donald Trump's administration announced this week that it would expel 60 Russian diplomats from the US and close a Russian diplomatic compound in Seattle in response to the poisoning of a former Russian spy in the UK.

The nerve agent attack against former Russian military intelligence officer Sergei Skripal and his daughter Yulia earlier this month is widely believed to have been ordered by the Russian government. The White House's expulsion, which was coordinated with similar expulsions of Russian diplomats by more than 20 other countries, signaled a resounding rebuke from the West against Russia's increasingly aggressive posturing.

But there's a catch.

A State Department official confirmed to Business Insider that the White House's diplomatic expulsion will not require Russia to reduce its staffing levels in the US, and vice versa. In other words, the 60 diplomats who were kicked out — many of whom were undercover intelligence operatives — can be replaced by others.

USA Today first reported the news on Friday.

The revelation initially gained traction in Russian state media, which said an anonymous senior White House staffer told the Russian government that it could send new diplomats to take the place of those who had been expelled. The Russian state media outlet Vesti quoted the official as saying, "The doors are open."

The Russian embassy in Washington currently employs 190 people, while the US embassy in Moscow has 1100. In response to the US' expulsion of 60 Russian intelligence operatives, Russia said it would respond in kind by expelling 60 US diplomats and closing the US consulate in St. Petersburg.

Targeted expulsions like the one announced this week are not uncommon. When former President Barack Obama expelled 35 Russian diplomats in response to Russia's interference in the 2016 US election, the move was made under similar conditions.

Russia, however, responded to Obama's targeted expulsion by ordering the US embassy in Moscow to cut its staff by 755 diplomats, meaning those who were kicked out could not later be replaced by newcomers.

A widening rift between Trump and his administration

Donald Trump. Getty Images

This week's expulsions will likely have little effect on Russia's intelligence-gathering or cyber operations.

But they are significant for one key reason, which the Russian foreign ministry unwittingly revealed in its statement this week.

"The provocative gesture of solidarity with London by these countries, who have bowed to the British authorities in the so-called Skripal affair and did not bother to understand the circumstances of what happened, is a continuation of the confrontational path to escalation," the foreign ministry said.

The primary objective of Russia's brand of information warfare against the West — known as "dezinformatsiya" — is to sow discord among nations Russian President Vladimir Putin considers hostile to his goal of reverting to the Soviet era. In many ways, the coordinated expulsions of Russian diplomats this week struck at the core of that intent.

The Russian foreign ministry's statement calling the move a "provocative gesture of solidarity" highlighted that Russia was not so much bothered by the act itself of diplomatic expulsions, but rather its signal that Western alliances still held strong.

Members of Trump's administration have sought to capitalize on the expulsions to push a more hawkish stance against Russia, but Trump remains unconvinced, reportedly telling advisers he favors a more cooperative approach toward Putin.

He is also said to have ordered aides not to talk publicly about tough measures he approves against Russia because he doesn't want to anger Putin.

Indeed, the US has taken a number of aggressive actions against Russia over the last year, including imposing sanctions, publicly blaming Russia for the widespread "NotPetya" cyberattack, shuttering Russian diplomatic compounds, and approving the sale of lethal arms to Ukraine.

Trump's silence, meanwhile, points to an ever-growing rift between him and his own national security apparatus when it comes to addressing Russia.