Pot, meet kettle.
Mexico is upset over this issue because Mexico's primary source of hard currency (particularly dollars) is the money sent home by illegal immigrants, and the "incursions" happened as a result of the rather useless 700-mile border fence currently under construction.
"Many Mexicans see the fence as offensive and say it will be ineffective and potentially cause more deaths in border crossings."
Here's an idea: if you're so worried about dying while crossing the border why don't you stay in Mexico?
The people who come into the US illegally are criminals. They break the law to come here; they break the law by staying here--and the reason they do is because they get away with it and we pay them to do it.
If we are not going to secure our borders--if we're going to let illegal Mexican immigrants come and stay here--why should we make anyone jump through legal hoops to stay in the US? I would like it if I didn't have to secure a visa for my girlfriend in the Philippines; why do I even have to, when Mexicans can just walk across the border and get all kinds of free stuff from my government? (Hell, why can't I get that amount of free stuff from my government?)
Sooner or later the issue of illegal immigration will reach a tipping point. Right now most Americans consider it a nuisance; if that gets worse, you will see barbed wire, land mines, and armed guards at the US-Mexico border, and people trying to get into the US from Mexico, illegally, will be shot.
If we have another major terror attack on US soil, and it turns out that the terrorists got in by flying to Mexico and walking across the border, expect that. Expect the Minutemen to be down there with semiautomatic rifles and guard dogs if our government doesn't do anything.
It's long past time to stop the hispandering and close the border.