A Response for Mr. Palmer

 In my post entitled, "Simply Complicated:  One Catholic's Response to the Bin Laden Brouhaha," the following quote proved ambiguous:

In the wake of such a socio-political tsunami, Christians would be wise to withdraw from shore, regroup, and carefully plan how to respond to the aftermath, rather than rush headlong into the tide, spouting choice prooftexts or joining in the chaos. Instead, they should reflect upon the Church's historical teachings and ponder the whole of Scripture; usually they will find that the "Christian solution" is equally multi-faceted.

In this post, I will attempt to elaborate upon this quote, as well as put forth other necessary elucidations that have been brought up in the post.

Mr. Palmer brings up a valid point:  this particular situation only really lends itself to two initial responses.  One can either choose to participate in the mob celebrations or refuse.  However, the act of refusal will necessarily peak the mob's curiosity.  They will inevitably question the rationale for this act; the Christian needs to have a better explanation than a few verses.  He doesn't need to have a treatise memorized verbatim, but he does need to have some sort of response for those who know enough about Scripture to respond to the favorite proof-texts with their own choice verses.

What I intended by this quote was this:  this world needs more than an army of Bible-thumping automatons who know three verses about "loving thy neighbor."  It needs a community of believers who have taken the effort to internalize Scripture, have relevant knowledge of the traditions of their community, and respond with a cogent, persuasive reason for their refusal to participate in the this orgy of nationalistic bloodlust. 

These things being said, I will attempt to present an example of how one might begin to formulate such a view systematically:

Scripture:  Throughout Scripture, we find general themes regarding creation and humanity.

 Creation is very good.  Humanity is God's unique creation, having been made in His image.  Mankind's state in Eden is that of benevolent steward over creation.  God laments Abel's death at the hands of Cain.  God indicates the great value of human life by demanding an account of any murderer; he institutes lex talionis: eye for an eye.  The Decalogue, which God gave to Moses on Sinai, includes among its tenets an injunction against murder.  Both Major and Minor Prophets preach about an idyllic, just, war-free society (Genesis 1-2, 4, 9; Exodus 20; Isaiah, Micah )  

Jesus Christ declares that he has come to fulfill the Law, rather than abrogate it, through His ministry and teachings , teachings which include loving one's enemies, refraining from violent resistance against oppression, and restraining one's hatred for others.   The Apocalypse of John promises that Heaven and Earth will become one, and God Himself will dwell among His people.  Edenic imagery abounds, indicating that the world to come will be a consummated Eden. (Matthew 4-7; Revelation)

Tradition

One has committed a mortal sin if and only if:
1.)  He commits it with deliberate consent
2.)  He commits it with full knowledge of its gravity
and
3.)  He commits it in a grave matter, i.e. the weightier of the Ten Commandments:  murder, adultery, theft, violating the Sabbath, etc. (CCC pg. 454)

The Catechism of the Catholic Church outlines the principles of legitimate defense:  one can only legitimately defend oneself in the instance of confirmed threat of life or limb.  Governments are allowed only punishment that is proportionate to the gravity of the committed offense.  The overriding principle which the Fifth Commandment upholds is that God holds life, especially human life, to be sacred.  Scandal, or acting or speaking in such a way that encourages another to commit evil actions, is akin to murder, if done willingly and knowingly.  Murderous anger, which is the desire for one's death or punishment that goes beyond mere desire for justice, is a sin.  (CCC  pp. 544-554)

Reason

Taking pleasure in Bin Laden's death is a sin, in that it damages charity.  It also does not spring from righteous desire for justice, but instead from sinful hatred of another human being, who shares in the common dignity of all human beings.  According to Jesus' teachings, hatred is murder.  Knowingly hating another person, in spite of knowledge of God's injunctions to the contrary, risks mortal sin.
 
This answer took about 20 minutes of thought to formulate, drew from several sources, and still wasn't comprehensive.  However, this is still leaps and bounds more substantial than merely quoting "love your enemies" in a tweet. Also note that I preferred citing whole books, rather than verses.  This is not merely because I wished to save time; I meant to emphasize that one needs to learn whole books and their shared themes, rather than mechanistically quoting verses as if they sufficed.  The Catechism is reference by nature, so quoting articles and passages is appropriate.