If you think in terms of neighbors, it is easy to see the pitfalls to "help" from the US. Here is a little to get you started:
You are a small, poor man, your next-door neighbor is a huge, (are you white? make him black. Are you black? make him white.) rich man, known to bully and force his way all over the neighborhood. You are working but not making enough to feed your family well, and your house is getting a little ragged. Your neighbor comes to your door with 5 of his huge, poorly-behaved sons (he can't bring them all because they are busy at other neighbors, fixing their lives) and informs you that you need help and they are going to fix things for you. You do need help, but you and your family are getting by. Your neighbor's house is in pretty bad shape, too, and you really aren't sure he knows what he is doing. You know his help will have strings, because he has helped you before, He uses your sons to make things in the little workshop he has set up on your side of the property line. You know he doesn't pay them enough for them to buy the things they make and he doesn't share the profit with you, then there is all that trash and garbage he leaves on your side. He got that fine for leaving it on his side, but no one fines him on yours. And you remember you used to have 1/3 more land before he decided many years ago that he needed it more than you and beat you up and took it. It was a long time ago and you're over it, but still... Do you let him in? Do you have a choice?
On the other side is the little old lady who wants to give or lend you money. She will also come live with you, since she is sure your wife is just not running your house correctly or you would have money. The fact that she owes billions and her children are on welfare and locked up? Not important, she will fix your finances and teach your children the right way.
When you want to help neighbors, you are friends first, then you ask, "Would you like some help? What can I do for you?" And you do it without thinking, "How can I get more than I give or get over on them?" You do it because what helps your neighbor helps us all.
So my answer is: we can- by using fair business, fair trade, fair everything in our dealings with them; by asking, without believing we know what is best for others, how we can help; by focusing on the very real problems we have in our own country- poor education, violence, drugs, gangs, dishonesty, lack of values, rudeness, hate, racism, etc. and working to change our country and make it better.
The people in Mexico, like the people in the US, do work and vote to make their country better. The military is not in cahoots with the crime bosses, nor is "The Government" corrupt. I live here, it is no better or worse than the US (where I have lived most of my life as a citizen) as far as corruption. There are always bad in with the good.