In a speech to Russia's parliament while formally annexing Crimea from Ukraine, Vladimir Putin cited history to legitimize his decision for “reunification.”

But it's another speech he made nine years ago that provides clearer insights into his motivations and end game. In 2005, Putin said during a nationally televised annual address that the dissolution of the Soviet Union was the “greatest geopolitical catastrophe of the 20th century.” It spelled the end of Russia as the nucleus of a world superpower and, according to Putin, left tens of millions of Russians outside the Russian Federation.

So based on that view, what does Putin think Russia should look like?

It's useful to study a 1989 map of Europe, just before Soviet republics began declaring independence and ending the Soviet Union two years later. In 1989, Putin was a 37-year-old lieutenant colonel in the KGB. From his perspective, the European map back then was how things were supposed to be.

Fifteen Soviet republics, spanning 11 time zones, from the Baltic Sea border with Poland, to the Russian Far East, north of Korea and Japan. From frozen Siberia on the Arctic down and across to temperate Sochi on the Black Sea.

Native Russian speakers were spread throughout the republics, including sizable populations in the Baltic states of Latvia, Lithuania and Estonia; Belarus to their south; and Ukraine further south all the way to the strategic Crimean peninsula in the Black Sea, which had been part of Russia prior to 1954 when it was "gifted" to Ukraine by Soviet Premier Nikita Khrushchev. The Caucasus republics of Georgia, Azerbaijan and Armenia became home to ethnic Russians, as did central Asian republics like Kazakhstan, Kyrgyzstan and Uzbekistan.

A strong leader on his third term as president after coming to power in 1999, Putin has branded himself as a Russian superhero. Which explains all publicity stunt photos — shirtless on a horse, shirtless with a rifle, hunting tigers, advancing another judo black belt degree, etc. He needs to show the world he’s tough and will crush any foes, internal or external.

So how does Putin restore Russia to greatness and fix the errors of 1989?

First, he matches that fearless Image with fearless acts. He’s ruthlessly crushed Muslim separatist movements in southern Russia’s energy-rich Caspian Sea regions of Chechnya and Dagestan, not hesitating to wipe out entire towns and cities that stand in his way.

Next, he’s committed to “protecting Russian speakers” wherever they are. Which is why when Russian speakers in two Georgian provinces bordering Russia, South Ossetia and Abkhazia, sought autonomy in 2008, Putin invaded Georgia to “protect” them. Those provinces remain under Russian control.

And when Ukraine’s European Union-friendly opposition ousted Putin’s man in Kiev, former President Viktor Yanukovych, it was Ukraine’s turn for “protection,” starting in Crimea. In one of the least plausible referendum results in modern history, a whopping 97 percent of the votes in a population of 2 million were in favor of union with Russia.

But why would Putin risk Western sanctions, economic isolation and expulsion from international organizations like the G-8? Because he knows Russia is in sharp decline. He must do something.

In 1994, Russia's population was 148 million. Today it's 143 million, shrinking for 20 years due to low birth rates, high divorce rates and high abortion rates. According to the American Foreign Policy Council's Ilan Berman in his book, Implosion: The End of Russia and What it Means for America, the Muslim population from southern Russia is 20 percent of the country's population and growing fast. If demographic trends continue, Russia could be a Muslim-majority country by 2050. And that scares Putin to death.

This is why Putin is so interested in “protecting” native Russian-speakers.

And while he’s annexed parts of Georgia and Ukraine so far, he’s likely far from finished. He’s got his sights on eastern Ukraine, plus Baltic nations, Latvia, Estonia and Lithuania. Less so on Belarus, though he has cut off its natural gas before.

But another reason Putin is aggressively reconstituting a “Greater Russia” is because he can.

He is confident that President Obama and European leaders won't take major steps to confront him. Obama and European allies must get tough, and stop showing weakness towards Putin's every move.

One way Obama can get Putin's attention is to remind him about the Budapest Memorandum of 1994, in which the United States, along with Britain and Russia, promised to defend Ukraine's territorial sovereignty in exchange for giving up nuclear weapons.

If Putin doesn't honor the Budapest Memorandum, Obama should abrogate the New START agreement. It was a terrible bargain for America to begin with, isn't verifiable, and does nothing about other nuclear powers China, North Korea and Pakistan, not to mention Iran's pursuit of a nuclear weapon.

The White House can push back on Putin’s power grabs — though it must start projecting strength, not weakness. It's the only force Putin truly understands.

J.D. Gordon is a retired Navy Commander and former Pentagon spokesman who served in the Office of the Secretary of Defense from 2005-2009. He is a Senior Adviser to several think tanks based in Washington, DC. Thinking of submitting an op-ed to the Washington Examiner? Be sure to read our guidelines on submissions for editorials, available at this link.