McCain, a Republican representing Arizona who largely disappeared from the public milieu after being diagnosed with brain cancer last summer, emerged unexpectedly after Trump's recent remark on permitting the return of Russia to the Group of Eight (G8), which is presently the G7 in Russia's absence.
"The president has inexplicably shown our adversaries the deference and esteem that should be reserved for our closest allies," the senator said in a statement Friday.
"Those nations that share our values and have sacrificed alongside us for decades are being treated with contempt. This is the antithesis of so-called ‘principled realism' and a sure path to diminishing America's leadership in the world," he added.
Curiously, McCain was not the first senator to make a stink about Trump's suggestion: earlier today, Chuck Schumer, a Democratic senator from New York, wrote on Twitter:
"We need the president to be able to distinguish between our allies and adversaries and to treat each accordingly."
It is interesting to note how seemingly the only issue that enjoys bipartisan support in Washington nowadays is ensuring the US president doesn't try and turn enemies into friends. Apparently, the lawmakers think the US should never attempt to engage in diplomacy and change the status quo in any way.
Trump remarked that "Russia should be in the meeting" while speaking to a group of reporters at the G7 summit in Quebec, Canada. Russia has been excluded since its 2014 annexation of Crimea, following that territory's referendum to leave Ukraine.
"They should let Russia come back in because we should have Russia at the negotiating table," he said.