Okay, maybe that needs a little clarification.
No, that's not a fake Captain America, it's the real Steve Rogers in the costume. He hasn't been mind controlled, and he's not lying to trick some villain. Those are his own words and his own opinions. Hard to believe, isn't it? So what's the deal?
The panel is taken from 1984's What If...? #44, "What if Captain America Were Not Revived Until Today?", by Peter B. Gillis and Sal Buscema, with a cover by Bill Sienkiewicz. A rather boring cover, in all honesty. Nothing against Sienkiewicz, but why would you pass up the opportunity to have Buscema do the cover if he's already doing the interior art?
Anyway, the story is this: instead of being found by the Avengers, Cap stays stuck in the ice. The Avengers did okay without him, but the team lacked heart, so eventually the members all drifted apart.
Then, in 1972, a janitor got pissed that Richard Nixon was going to China, so he thawed out Captain America and Bucky - not the real ones, but the Communist-hating lunatics from the '50s (though we don't know that at first). It simply proves that the great thing about America is that one man can make a difference: the tragedy of America is that it requires that one man to actually be smart and well-informed.
Things start out okay: FakeCap stops a bank robbery (perhaps a bit too violently, but not to an extent that draws any notice) as a way of reintroducing himself and his partner to modern law enforcement; they even defeat quite a few supervillains. Everything seems normal, until he appears on a few talk shows.
FakeCap and Bucky are approached by a representative from the Committee to Regain America's Principles, "a group of concerned citizens, trying to save America from moral bankruptcy." The man from CRAP offers them financial support, and in return they begin promoting his candidate, Norman Chadwick, for senator.
When FakeCap and the police assemble to stop a protest march, he's shot by a sniper (who secretly works for his bosses). The police attack the black protestors, sparking nationwide riots that allow the government to crack down even harder. Martial law is declared, with FakeCap's support, and a new private police force known as the Sentinels of Liberty is formed.
Then, in 1983, a nuclear sub on patrol in the North Atlantic comes across a man-sized chunk of ice. Hauling it aboard, they find the real Captain America inside. At first the crew mistakes his uniform for evidence that he supports the Sentinels of Liberty, so there's a brief fight, but the captain of the sub was around during WWII and recognizes Cap's moves. He puts a stop to the scuffle, and educates Steve about the modern world.
The military is the only place free from the government restrictions, so servicemen are watched over by the Sentinels of Liberty. Newspapers still exist, though they're heavily censored under the Emergency Information Freedoms Act. The skipper takes Cap to see one of the men who refused to be silenced, J Jonah Jameson. JJJ sneaks them onto a delivery truck that takes them north to Harlem, which is now enclosed behind a high concrete wall.
They meet up with the resistance, led by Nick Fury with his lieutenants, Spider-Man and the Falcon. Falcon doesn't trust Cap, but Nick Fury recognizes him as the real deal.
Meanwhile, FakeCap meets with his bosses in "the America First Party" - who turn out to be members of several Marvel villain groups: the Secret Empire, the Sons of the Serpent, and others that Captain America fought against in the 616 continuity.
At Madison Square Garden, FakeCap and his super-team, the Freedom Five, speak at the America First Party's national convention. Suddenly Cap and his allies drop from the rafters! Spider-Man webs up Hawkeye and Hangman, Nick Fury holds a gun on Bucky, and the Black Cadre (Falcon and his crew) just let Golden Girl escape, because she's an actress hired to fill a costume, not a real threat. What follows is an epic three-page fight between Cap and FakeCap (some of which is swiped from the Batroc fight in Tales of Suspense #85, but it's too cool for us to hold that against it) as tanks break out through the walls of Harlem and other cities across the nation.
Cap is victorious and the FakeCap falls, but the audience believes that Cap, Spider-Man and the rest are traitors. They threaten to storm the stage, but then comes the high point of the issue: Cap delivers an impassioned speech to the crowd, telling them what America means, and what's gone wrong with the country in his absence.
My god is that powerful! That should be taught in every high school civics class in the United States. That is patriotism, right there: you aren't a good person because you're American, America is great because you're a good person. There are so many politicians, pundits and protestors who all need to hear that lesson, to let it sink in, and to learn the difference between patriotism and nationalism...