Saying "depends on the regulation" is not in any way saying that regulations don't "make us safe"
A very large cow - my point remains.
You said it yourself, infectious disease - no infected animals in the U.S., no spread of diease, import an infected cow, import the disease. Let diseased animals infect each other, they poison humans. We import cows from lots of places, no mad Cow disease in humans - coincidence?
Help Ive fallen into the logical hole in your argument and can't get out! Regulations by themselves do not make food safe, only those regulations that are acted upon and enforced make food SAFER, but not perfectly safe since no human system can ever be perfect. There will always be things that get through and cause harm the regulation was intended to mitigate. Always.
We sell the very large cows for slaughter, we get paid by the pound. Cows are very docile creatures, they don't break fences much, sheep on the other hand find ways through fences that you wouldn't imagine could be found.
If cows break the fence everyday I move the cows, if it is a one time occurrence I fix the fence, your solution is to fix the fence no matter how many times they break it. But worry not, once all the garden veggies have been eaten they will no longer break the fence. You are going to starve though because you didn't have the logical thought process to see that the cows were the problem, not the fence. Next year, move the garden.
Sorry to tell you the truth, but there have definitely been cases of importing cows into the USA with Mad Cow (BSE). Besides you don't get it from importing cows with the disease, some cows just come down with it. I suggest you do more reading on the subject before espousing how flawless the BSE record is here in the USA, you are just deceiving yourself. Some might call it being ignorant, but I truly think you thought that mad cow had never reared its ugly head in this country. people are living with the disease here in the USA right now.
http://www.cdc.gov/ncidod/dvrd/bse/