Mexican law enforcement protecting us from terrorism?

Here it is on the FEMA website.

From the link:

NLE 09 is a White House directed, Congressionally- mandated exercise that includes the participation of all appropriate federal department and agency senior officials, their deputies, staff and key operational elements. In addition, broad regional participation of state, tribal, local, and private sector is anticipated. This year the United States welcomes the participation of Australia, Canada, Mexico and the United Kingdom in NLE 09.

I could understand law enforcement observers from foreign nations, but participation? Seems to me that Mexican law enforcement has more than they can handle now with their own country.

Why would anyone from Australia or the UK be participating? Officials from Canada and Mexico could just drive across the border but the one's in Australia would have a little more trouble than that.

The NLE 09 scenario will begin in the aftermath of a notional terrorist event outside of the United States, and exercise play will center on preventing subsequent efforts by the terrorists to enter the United States and carry out additional attacks.

I'm not sure what they are planning but I'll bet dollars to donuts it's not closing the border.

This doesn't make me feel more secure.