As Muammar Qaddafi's forces continue their assault on the western town of Misrata and drive the Libyan rebels back east to Ras Lanuf, Brega, and now as far as Ajdabiyah, rebel leaders are stepping up their appeals to the international community for better weapons.

U.S. and U.K. officials--including President Obama--say they haven't ruled out the option of arming rebels, while France says it's willing to entertain the idea outside the framework of the U.N.-authorized mission in Libya. Russia, however, is vehemently opposed to such action. At the heart of the debate is the question of whether arming the rebels would be legal under the U.N. mandate in Libya. And at the heart of the legal debate, apparently, is one word: "notwithstanding."

Here's why: U.N. resolution 1973, which called for military intervention in Libya, authorizes member states to "take all necessary measures, notwithstanding paragraph 9 of resolution 1970 (2011), to protect civilians and civilian populated areas under threat of attack" in Libya (emphasis ours). When the U.N. says "paragraph 9 of resolution 1970," it's referring to a previous U.N. resolution that established an embargo on the sale of arms to Libya.

The BBC explains that "notwithstanding" is a "lawyerly word meaning 'in spite of.'" Some people, therefore, interpret the word as signaling conditions under which member states would be exempt from the arms embargo.

The British Foreign Office, for example, interprets the "notwithstanding" clause as overriding the arms embargo, according to The Guardian. "If the only way to protect a civilian area was to arm the population of that area," The Guardian explains, then, according to the Foreign Office's logic, "it would be legally permissible.We have seen how the principle of protecting civilians through air strikes has been stretched to targeting government forces wherever they can be found. If implemented, would the principle of arming civilians and their defenders prove equally flexible? Probably."

Other legal experts are interpreting the U.N. resolutions differently. A professor of international law at the University College of London told The Guardian that the international community can't arm the rebels because the arms embargo clearly covers every party in the Libyan conflict. Another professor says resolution 1973 actually strengthens the arms embargo by calling for its "strict implementation" by member states.