In the 100K+ miles I've flown since 9/11, the only countries that don't allow metal knives are the U.S. and U.K., although I haven't been to Australia recently.

The only exception is AF which had plastic both on domestic flights and a AMS-CDG flight. I was quite shocked that AF would allow the Germans (LH) to have decent silverware while AF had plastic.

I'm flying EZE to SCL tomorrow so I'll see if they have metal on LA.