New cold war?

We have seen that the last years (under Putin and now Medvedev) Russia has taken a more agressive course against the rest of the world.

We have seen:
The gascrisis with Europe.
The war in Georgia.
The opposition against the rest of the world in conflicts.

And many more..

Do we have to be affraid again of Russia? Are they going to be once again one off the greatest nations in the world?

Let me here your opinion !