In his attempt to wrest a greater role for himself and his followers in Karbala, the cleric's militia clashed with government forces, leading to the arrest of some 300 militiamen, according to a statement issued by Prime Minister Nuri al-Maliki's office on August 16. While observers say the cleric poses no real threat to Iraqi security, al-Hasani claims thousands of supporters across southern and central Iraq.

Al-Hasani appears to have risen to prominence following the fall of the Saddam Hussein regime in 2003 through his staunch opposition to the U.S. invasion and the subsequent establishment of the Iraqi Governing Council. He later opposed the interim and transitional governments, as well as the December 2005 election that brought the current government to power.

Al-Hasani stands strongly opposed to Iranian influence in Iraq, and has criticized Iranian-backed political groups operating in Iraq, such as the Supreme Council for the Islamic Revolution in Iraq (SCIRI) and the Al-Da'wah Party, which is led by Prime Minister al-Maliki.  

While he opposes Iranian influence, al-Hasani does support the establishment of an Iranian-style Islamic theocracy in Iraq. A former student of Iraqi Ayatollah Muhammad Sadiq al-Sadr, al-Hasani subscribes to vilayat al-faqih, or rule of the jurisprudent, as practiced in Iran.