Negotiations for a unity government between Fatah and Hamas are the fruit of international pressure, which has forced Hamas to consider sacrificing some of its formal authority within the Palestinian Authority (PA) despite the fact that the Islamic movement and its allies hold 77 out of 132 seats in the Palestinian Legislative Council (PLC).

How the international community should react to Hamas-Fatah coalition negotiations depends in part on whether international pressure has also reduced Hamas's more informal sources of authority. If Hamas retains meaningful authority outside of PA institutions, forcing it from government would simply make the PA ineffective in serving the needs of either Palestinians or Israelis. Measuring Hamas's power relative to that of Fatah requires a look at its three bases: social services, military force, and popular support.

Palestinian and foreign observers ascribed Hamas's victory in 2005 local elections and 2006 legislative elections to its network of efficient and honest social service providers. These social service networks are more than just a basis of Hamas' popularity; they are also an indication of its organizational strength. While it is difficult to measure Hamas's social services precisely—it does not publish disclosure forms or annual reports—United Nations officials report that it remains as active as it was prior to the election. The stifling financial sanctions that have all but eliminated the PA's ability to provide government services have not, apparently, diminished Hamas's capacity to provide services on a smaller scale.

Hamas's military power gives it the ability to launch terrorist attacks on Israel and to fight Fatah military groups. From either perspective, military power equates to real authority within the PA. While it is also difficult to measure Hamas's military power directly, it is possible to observe its use. Clashes between Hamas and Fatah forces in Gaza since the beginning of October indicate that Hamas has, at the very least, retained a rough military parity with Fatah. Despite Israeli incursions targeting Hamas military forces, news reports indicate that one of Hamas's armed groups, the Executive Force, has become strong enough to force some Fatah commanders to leave Gaza.

Regular public opinion polling in the PA makes Hamas's popular support somewhat easier to measure. In the legislative election, Hamas and Fatah were close in terms of their share of the popular vote, with Hamas winning 44 percent to Fatah's 41 percent. Most opinion polls prior to the election showed Fatah with a small lead over Hamas, an error probably due to methodological problems in polling and an understandable reluctance of respondents to admit support for Hamas given the possibility of Fatah or Israeli reprisals. Immediately after the election, support for Hamas in polls jumped to just over its election result of 44 percent, perhaps indicating a combination of a honeymoon for the new legislative council and a reduction in respondent fear.

While it is possible to cite more recent polls, or parts of more recent polls, as evidence that Hamas is loosing substantial support, the broader trend in polling data indicate that Hamas and Fatah remain evenly matched. Polls since June show support for the two parties settling at about 40 per cent support for each, although the most recent reputable poll shows a reduction of support for both parties, with Fatah at 35 percent and Hamas at 31 percent. Given the margin of error, methodological problems, and possible respondent fear factor, this result should also been seen as evidence of generally equivalent public support. Looking deeper into the polls, while Hamas has a 44 per cent negative rating for its role in post-election crises and a 60 per cent “poor” rating for implementation of its election program, 62 per cent still support Hamas's most important decision: not to recognize Israel.

After seven months of severe political and economic crisis, including the virtual closure of Gaza and financial cut-offs leading to 170, 000 PA employees being paid less than two months' salary, Hamas has indicated a willingness to negotiate an agreement to share formal authority in the PA. But while continued pressure may succeed in forcing Hamas to cede more (or all) of their formal authority within the PA, experience thus far does not indicate that it will undermine Hamas's other sources of power.

In December 2005 and January 2006, the international community pressed the PA to conduct PLC elections as scheduled, overcoming strong Fatah reservations to the electoral process. In part, the international community took this position because the Fatah-led government did not reflect real power relationships in the PA and so was unable to deliver meaningful reform of PA institutions or improvements in security for Israel. In making decisions now about whether to accept a potential government of national unity, the international community must take into account Hamas's real and apparently enduring strength.