Of course you could do more - you can always do more, and you should do more - but still, the important things is to do what you can, whenever you can. You just do your best, and that's all you can do. Too many people use the excuse that they don't think they can do enough, so they decide they don't have to to do anything. There's never a good excuse for not doing anything - even if it's just to sign something, or send a small contribution, or invite a newly settled refugee family over for Thanksgiving.