why the us & uk are going in so hard in libya

It is an example to anybody in the region who has thoughts of attacking Israel or Saudi Arabia. The Big West 2 has to put on a shock and awe every few years to let everybody know that they are still top dog. Russia and others may be mumbling under their breath but know that they cannot do anything about it. Germany would be in it also except they have elections getting in the way. This is why submarines were used as well, although unnecessary.