President Donald Trump and his allies have a ready-made defense for whenever he viciously attacks his opponents: He’s a counterpuncher.


“Remember, one thing that everybody has said: I’m a counter-puncher,” he told The Washington Post during the GOP primaries last year. “I’m a counter-puncher,” he told CNN in September 2015. “You understand that; I’m responding,” Trump told Megyn Kelly in May 2016. And Trump does indeed like to respond - bigly. He’ll bring a bazooka to a knife fight. If you attack his policies and his temperament, he’ll go after your family. Ask Ted Cruz.


But there is one topic on which the counter-puncher-in-chief is conspicuously gun-shy, and has been for a long time: Russia.


This weekend, Russian President Vladimir Putin announced he would order 755 personnel out of U.S. missions in Russia in response to new U.S. sanctions against his country for its interference in the 2016 election. According to The Post’s Andrew Roth, it’s “the single largest forced reduction in embassy staff, comparable only to the closing of the American diplomatic presence in the months following the Communist revolution in 1917.”


Trump’s response to this has been silence. He has not tweeted about it since the news broke, and he’s instead left the messaging to Vice President Mike Pence, who is touring Eastern European countries who are also anxious about Russian interference. “The president has made it very clear that Russia’s destabilizing activities, its support for rogue regimes, its activities in Ukraine are unacceptable,” Pence said, adding: “As we make our intentions clear, we expect Russian behavior to change.”


Trump, to his credit, has indeed delivered a message about Russia’s actions with regards to Ukraine and others, saying earlier this month that it must “cease its destabilizing activities in Ukraine and elsewhere” and end its support for “hostile” governments in Syria and Iran. Pence also pointed out that Trump has said he will sign Congress’s new Russia sanctions bill, but it’s not really even a choice for Trump: Congress has way more than enough votes to override his veto.


That’s about the full extent of his tough talk for Putin; he’s never really applied any pressure when it comes to Russia’s interference. And now that Putin is taking bona fide, retaliatory measures for U.S. sanctions, Trump would generally be expected to hit back. He hasn’t. Russia has apparently given up on an alliance with the United States, but Trump hasn’t seen fit to send a message about why that’s a bad idea.


That’s a marked contrast to how Trump has treated other countries’ leaders. To wit:


—When China’s actions with regard to North Korea have appeared insufficient, Trump has repeatedly tweeted about it. Trump tweeted just this weekend: “They do NOTHING for us with North Korea, just talk. We will no longer allow this to continue. China could easily solve this problem!” Recently, he suggested he would rethink the U.S.-China trade partnership in retaliation for Beijing’s failure to help: “So much for China working with us - but we had to give it a try!”


—Back in June, Trump attacked London Mayor Sadiq Khan for his handling of a terrorist attack, taking Khan’s quotes out of context. “At least 7 dead and 48 wounded in terror attack and Mayor of London says there is ‘no reason to be alarmed!’” Trump tweeted.


—He has regularly complained about allegedly unbalanced NATO funding and trade deals with Europe. “We have a MASSIVE trade deficit with Germany, plus they pay FAR LESS than they should on NATO & military,” he tweeted in May. “Very bad for U.S. This will change.” He added in January: “How many Chevrolets do you see in Germany? It’s gotta be a two-way street - I want it to be fair.”


—Trump has also repeatedly accused Qatar of funding terrorism and supported the blockade by other Middle Eastern countries, complicating efforts to relieve tensions in the region and contradicting his own secretary of state’s call for a more diplomatic approach. “The nation of Qatar has unfortunately been a funder of terrorism, and at a very high level,” Trump said last month.


The common thread running through many of these is an implied threat - doing something if other countries don’t bow to Trump’s will. And Trump will often hit back hardest when he thinks someone isn’t giving the U.S. the respect it deserves.


With Russia, we very much have a situation in which Putin is pressing the issue. The longer Trump is silent, the more conspicuous it is.


Aaron Blake is a Washington Post columnist.