I was thinking of writing my Congressman and Senators to advise against cutting off aid to Pakistan, but after reading through this thread it seems as if at least on this board the consensus among Pakistanis is that they wish to have aid from the US cut-off anyway. If that is the case than America probably should then.
There is no such thing as Free Aid. US Aid always comes with strings attached. First and foremost it is an essential instrument of the foreign policy. Indirectly it helps US economy also puts surplus US military equipment to good use.
For example if surplus F-16s are not given in Aid these will eventually be destroyed or sold off as scrap. Some might even be used as drones for target practice. Currently the old ones are given free but US arms industry sells MLU kits as well as large quantities of arms, ammunition and spare parts. Same applies to naval vessels.
Similarly, economic aid goes a long way towards helping US industry. Even PL-48 aid (actually paid back in local currency) was in actual fact a help to US farmers. It is therefore in as much interest of the US to give Aid as it is in the interest of 3rd world countries such as Pakistani to receive it.
Unfortunately, for whatever reason, only Western Europe, Japan, South Korea and Israel have really benefitted from this generosity. Most other countries, particularly Egypt & Pakistan have not been able to put US Aid to good use. Consequently, despite a substantial injection of US aid during the last decade, majority of the population in these countries harbours a deep mistrust of the US.
Besides, a lot of aid is in the form of long term soft loans. I for one would not support Pakistan to carry on living on borrowed funds indefinitely.