Sweden and Finland applied for NATO membership today. All indications are there will be a hasty approval.
The NATO alliance is a good one—closer to the U.N.'s original remit than just a military alliance.
Therefore—crazy idea alert!—I think NATO should extend membership to Russia, even if they don't ask for it. Mutual defense means you cannot declare war on a neighbor, and Putin has been CLAIMING that Russia's moves are all defensive, not aggressive. If he fears aggression from NATO, let him be forced into membership.
Strategic trade agreements and lowering of tariffs and sanctions could only be a good thing. Let the olive branch be extended. Let Putin explain to the world how that would not be a benefit to his country.