Speaking strictly on reducing the deficit, it would be foolish, neigh, a crime to make our cuts in defense and pensions. First, our defense budget is in place to keep us ALL protected in this great country. In case you didn't know, there are multiple people and groups out there that wish us gone; vaporized off the face of the earth. Combining this with the already bone deep cuts to this part of the budget (ask anyone in the military, these cuts are already happening and are powerful), removing further funding could impact the safety of all United States citizens. Personally, I like being protected, and only a fool would wish cuts to this. If a government isn't there to protect its citizens, what purpose does it serve?
On the topic of pensions, a more moral decision arises. As pensions are something every working man and woman pays into, a cut to these is basically a retroactive sequestering of their income; robbery in short. Last time I checked, thievery in the USA is crime, and just because the government is doing it doesn't mean it's not. These people have payed into this program, the government has no right to steal from them just to cover their butt.
Even if these two sectors aren't touched (which they have been, military funding is unfortunately dropping drastically year to year), this still leaves 54% of the budget pie to cut. Welfare might be the smallest slice, but it is a slice nonetheless. A discontinuation of the blatant handouts to lazy ne'er-do-wells raised on the governments teats is a start. Now, lets take a look at the remaining 44%. While we could get into a pissing match focused just on health, let's just suffice to say that no matter who you are, most agree that it can be done more efficiently, and thus, cost-effectively. This still leaves another 20% in the remainder. Other than payment to government workers, which doesn't comprise this entire sector, there are definitely cuts to be made here. If you haven't heard of a government program that just made you scratch your head, then you must not get out enough. Programs such as these could easily be cut as well. If you wish for me to pull up a list of ridiculous programs, I will happily (actually unhappily due to the stupidity of our budget) do it.
There are cuts to be made, but only a fool or criminal would want further cuts in defense/pensions.