stockhausen wrote on 01/20/19 at 11:59:27:
this black's position always feels really solid and I don't know what white's plan is for this position. Can someone please help?
Another good reason not to play 3.Nc3 is Bxc3+ 4.bxc3 f5, heading for a favourable Dutch.
IM Bronznik spends an entire chapter on the Keres Defense 1.d4 e6 2.c4 Bb4+ in Beating the Guerillas. Acoording to him White hasn't any better than heading for a relatively good Bogo with 3.Bd2 Bxd2+ 4.Qxd2 Nf6 5.g3 O-O 6.Bg2 d5 7.Nf3. Though IM Bronznik doesn't explicitly formulate it the plan seems to be (note that I'm hardly qualified in this respect) preventing Black from playihng ...c5 and from ...e5 or making him/her pay a price as high as possible. I quote:
"I admit that [this line] promises Black good chances of equality. On the other hand, please do not underestimate the fact that we are talking about the sort of positions in which one of only two results is possible and [Black] is the one who is trying to achieve equality, not you."
Another problem line he identifies is 4...f5 5.g3 Nf6 6.Bg2 O-O 7.Nc3 d5!? 8.Nf3 c6.
"GM Glek wrote in SOS Vol.9 that Black achieves an absolutely acceptable Stonewall set-up despite the absence of the dark-squared bishop, and he backs up this opinion in his games."
So IM Bronznik recommends 7.Nf3, hoping that moving the queen and developing the knight to d2 offers an edge. Indeed GM Glek prefers 7.Nf3 d6 8.O-O Qe7 9.Nc3 c6 and only then 10...d5.
If all this is not ambitious enough to your taste you'll have to consider 2.e4, I'm afraid.