Sen. John McCainJohn Sidney McCainTrump considering pardon for boxing legend after call from Sylvester Stallone GOP poised to advance rules change to speed up Trump nominees The Hill's Morning Report: Inside the Comey memos MORE (R-Ariz.) wrote in an op-ed Friday that the Russian people will someday overthrow President Vladimir Putin, and the United States should “prepare for that day now.”

“Eventually, Russians will come for Mr. Putin in the same way and for the same reasons that Ukrainians came for Viktor F. Yanukovych,” McCain wrote in The New York Times, referring to the Ukrainian president ousted by protests last month.

McCain penned the op-ed ahead of a Sunday referendum in Ukrainian region of Crimea, now occupied by Russian troops, on seceding and joining Russia.

McCain said Russians will take inspiration from Ukraine’s recent uprising and someday rise against Putin. 

“If Ukraine can emerge from this crisis independent, prosperous and anchored firmly in Europe, how long before Russians begin to ask, “Why not us?” McCain writes. “That would not just spell the end of Mr. Putin’s imperial dreams; it would strip away the lies that sustain his rule over Russia itself.”

“We must do all we can to demonstrate that the tide of history is with Ukraine — that the political values of the West, and not those of an imperial kleptocracy, are the hope of all nations,” he wrote.

He calls for stronger sanctions against top Russians and welcoming neighboring countries such as Ukraine, Georgia and Moldova into the “Euro-Atlantic community.”

McCain also writes the Russian invasion of Ukraine is not President Obama’s fault but that Obama’s policies, most of all not punishing Syria's president for using chemical weapons, made Putin think the U.S. has a “lack of resolve.”