Is Russia still a threat to the US?

Yes and no. Militarily, they are weak. Their air force and navy are, to be kind, not well respected world wide. In modern warfare, an army is practically useless without air superiority or at least air contention. Their armies in Ukraine could be eliminated in a matter of weeks. However, they do have intercontinental ballistic missiles that are or could be armed with nuclear warheads and that is a threat. Of course, it'd be a last ditch move so extremely unlikely in a war limited to Ukraine or whatever other countries they invaded.

Really, everything Putin does is for home consumption - to keep him and his fascists and the mafia in power so he's more of pain in the bass then a threat.

At present Putin poses threat for the whole world.

No, it is not.

They never were that much of a threat. And now less than ever.

No, they are only helping keep the peace in Ukraine with a peaceful army presence; and Mr Obama needs to speak to Mr Putin and other Leaders to help Ukraine regain a good and non Corrupt Leader for Ukraine.

I can't believe the other Answers.....YES....Russia is still very much a threat to the US.
After the fall of communism (1991-1993) I thought the two powers should have joined up in alliance but their politicians never did.
In 2014 Russia is on the march again...a 1 million man military/ 1400 combat aircraft, a fleet of submarines and surface ships....PLUS....the worlds 2nd biggest nuclear arsenal of about 1000 nuclear warheads of about 1000 megaton total yield (enough to blow up the world).
The US beats them only in numbers.....1.3 million person military, 5,000 combat aircraft, more surface ships and submarines, 4,000 nuclear warheads (enough to blow up the world twice). But that certainly would not guarantee we are safe from the new mighty Russia that's marching again.
I think the 'Cold War'....is....back.

The old Soviet Union were a threat due to it being Communist,but since 1991 Russia has been an elected democracy and no threat to the west at all

Since their alliance with China a few days ago they could be a threat. In politics things can change from friend to enemy overnight.

I think the USA is p!ssed off because they thought they were the only country who could invade someones sovereignty.

No big-Country is a threat to another big-Country(even the Cold War was a political one, not a real one), because neither will want to fight each other, too much losses.

Russia is armed with weaponary that can blow-up the World, just like the US, so both also know they better not try, because they can both blow us into oblivion.

So no, Russia is just policing a Country that has a majority of Russian in the area they stabilized, which is pretty much exactly what NATO, and the US would do(and ARE doing in North-Africa, and the Middle-East).

Don't get sucked into Cold War sentiments, Russia isn't doing anything we wouldn't have done exactly the same.
We actually did when Europe developed as Independent Countries, the Netherlands, Belgium, and Luxemburg were 1-Country until the 19th Century Belgium first, then Luxemburg became independent.
Prusia pretty much the same, a collection of different Ethnicities, and Peoples, that expanded until the 19th Century after which the Countries seperated.

The Soviet Union ended in the early 90s, the borders set then, aren't necessarily the right ones(especially in the Ukraine, because Khrushchev gave the Ukraine the East, and Crimea as a gift in the late 1950s(because he loved the Ukraine), it originally was Russian soil) , and the culture obviously didn't 'take' on Crimea, and in big-parts of the East-Ukraine.

It's why instead of talking war, and sanctions, we should be talking Referendum to see what the people of the areas in Ukraine want, because it could very well be, that the people in East-Ukraine, and Crimea want to be Russian, and will vote so democratically(which they have already, it's why Yanukovich got elected, for his desire to reach out to Russia).

Basically it's time to acknowledge West-Ukraine, and East-Ukraine are 2 very different places, where the people want 2 very different things, there should be a way to make both sides happy, simply by acknowledging who the people of the land are.