Since ISIS declared the establishment of its caliphate just over a year ago on June 29, 2014, it has seen its territory grow and shrink. According to one estimate, ISIS has lost a quarter of the territory it once controlled in Iraq. While it still controls key cities like Mosul and Ramadi, it has also seen battlefield defeats since its rapid expansion last summer.

While progress against ISIS in Iraq can be attributed to many factors, including American airstrikes, the bravery of Kurdish pesh merga fighters, and the pushback by Iraqi forces, the catalyst for these changes lies in the political and military reforms under the government of current PM Haider al-Abadi following the conclusion of Nouri al-Maliki's premiership in September 2014.

The origins of Iraq's political and military disarray can be attributed in part to Iran's influence in 2010 and its diplomacy that kept al-Maliki in power.

In Iraq’s 2010 parliamentary elections, incumbent PM al-Maliki’s bloc of parties did not win the most votes. However, Ayad Allawi, the leader of the secular bloc that captured the plurality of votes, was unable to cobble together a government. In the interim, the leader of Iran’s paramilitary Quds Force, Qassem Suleimani, brokered a deal to keep al-Maliki in place.

In exchange for persuading the Shiite Sadrists to back al-Maliki, Iran was told the Iraqi government would push to have American troops exit the country by the end of 2011. The White House acquiesced to this deal, despite fears on both sides about the consequences of a premature withdrawal of American forces.

After al-Maliki formed the new government, he began to consolidate political power. For instance, when the Integrity Commission discovered that his cabinet was involved in a network involving the issuing of contracts to fake companies, al-Maliki blocked the prosecutions and later replaced the commission’s director with an ally. Also, after Americans withdrew militarily in 2011, Maliki had the leading Sunni politician, Vice President Tariq al-Hashemi, arrested.

Al-Maliki also controlled and politicized the country’s security forces. He became reliant on a pro-Iranian militia, Asaib Ahl al-Haq (AAH), for personal security as American forces began to draw down in 2009. For much of 2011, he served as the acting minister of interior and defense. He also created the Office of the Commander-in-Chief to circumvent democratic controls, and he used his enhanced powers to create a network of patronage across the country.

Graft became especially commonplace, as high-ranking military leaders used their positions to grow their own wealth.

Reuters quoted one American source claiming that senior military officials were “picked because al-Maliki values their loyalty to him over any kind of war-fighting skills.” This inexperience was exposed in June 2014, when ISIS made its rapid conquests across northern and western Iraq.

One such al-Maliki appointee, Gen. Mahdi al-Gharawi, not only had a record of torture and sectarian persecution of Sunnis, but was so notoriously corrupt that he earned the nickname “General Deftar” – a reference to the 10,000-dinar note.

Al-Maliki had long protected al-Gharawi from persecution – that is, until the general, tasked with defending Nineveh province, was embarrassed by the swift defeat at the city of Mosul. Finally, al-Maliki relieved Gen. al-Gharawi of his position.

After the fall of Mosul, the country's second-largest city, Iraq's leading Shiite authority, Grand Ayatollah Ali al-Sistani, called on all able-bodied men to join the fight against ISIS. Distrustful of the faltering national forces, many joined local and sectarian militias. As the commander-in-chief, al-Maliki created an umbrella organization for these various militias called the Popular Mobilization Forces (locally referred to as Hashd).

The corruption and politicization of the security forces under al-Maliki, meant to cement his control, backfired as ISIS’s advances coincided with the upcoming parliamentary elections of 2014.

Though al-Maliki’s bloc garnered the most votes in the April 30 election, with the absence of a clear majority, months of

political bargaining occurred while Iraq suffered several rapid military defeats.

Again, Iran served as the de facto kingmaker. In negotiations, this time Iran expressed disapproval with al-Maliki’s incompetence and divisiveness, especially as ISIS captured the city of Jalawla just 25 miles from Iran’s border. Al-Sistani told Iranians in secret that al-Maliki should be replaced.

Al-Monitor quoted a source saying that Iran wanted to "support a name that wouldn't intimidate the Sunnis and the Kurds” and eventually settled on the Shiite politician Haider al-Abadi. Several dozen lawmakers from Maliki’s bloc pledged their support for al-Abadi, and he was declared prime minister on August 11 and approved by the parliament on September 8.

Al-Abadi immediately began governing in a style opposed to that of his predecessor. Politically, he appointed a cabinet that reflected the country’s diversity. In October, the parliament approved the nomination of a Sunni, Khaled al-Obeidi, as Iraq’s defense minister.

Al-Abadi’s government also quickly sought to undo the damage that al-Maliki had done to Iraq’s security forces. He replaced 36 top officers that had been appointed by al-Maliki.

His cabinet also took a significant step by bringing the Hashd militias under state control in order to curtail the sectarianism and mistreatment of locals that had eroded Sunnis' trust in Baghdad.

This conciliatory and nationalist reform was symbolized by al-Abadi’s visit to Habbaniya on April 8, where he not only celebrated the country’s recent liberation of Tikrit, but also held a swearing-in ceremony for Sunnis joining a local militia. Al-Abadi even personally handed out rifles to the new recruits.

To enhance accountability, al-Abadi has proposed that all new weapons dispersed to militia fights should be imprinted with serial numbers.

The victory in Tikrit was soon overshadowed by the loss of Ramadi in May. While U.S. Defense Secretary Ashton Carter commented that the Iraqi's showed they lacked a "will to fight" by abandoning Ramadi, analysts contend that the Iraqis successfully held the city for 16 months before finally being outnumbered and overpowered. The BBC also reported that the brigadier in charge of the city had been convinced that ISIS was prepared to use explosive devices in the city center and thus ordered a hasty retreat.

Nevertheless, despite al-Abadi's reforms and some successful military operations (including progress in reclaiming Beiji, the site of a strategically located oil refinery), more needs to take place before the country will be prepared to defeat ISIS – especially given that an estimated 22,000 Iraqi troops have deserted their units.

Politically, al-Abadi's government has withstood internal pressure – most notably from the Shiite opposition centered around al-Maliki and pro-Iranian militias. For instance, it dismissed a call by some Shiite militias to delegate more autonomy to the Hashd after it was criticized for a massacre at the military outpost of Tharthar, where a disputed number of troops were killed in an ISIS ambush. It faced similar criticism and demands after the fall of Ramadi.

Balancing the array of allied combatants – domestic and international – in the fight against ISIS will nevertheless prove to be al-Abadi's toughest political challenge. While it has benefited from American support in terms of timely airstrikes and hundreds of new personnel – including the recent dispatch of 450 Americans to

train Sunnis at al-Taqaddum Air Base, victory against ISIS will have to come at the hands of Iraqi fighters who may be difficult to control.

To reclaim lost territory in the Sunni-populated Anbar province, the government is trying to reduce its reliance on Shiite militias. Though state security forces are likely to lead the fight to retake Ramadi, it appears as though powerful Shiite militias will be central in the upcoming battle in Fallujah. Al-Abadi repeatedly stresses the nationalistic and pan-sectarian nature of the victories against ISIS, but the leaders of Shiite militias like AAH and the Badr Organization routinely frame the military contest in explicitly sectarian terms.

To prevent sectarianism from interfering with the fight in Anbar, al-Sistani called on the militias to respect the property of the area's inhabitants and to make them feel safe.

In some battles, Sunni and Shiite militiamen are fighting side-by-side to defeat ISIS.

"We are all here. Sunni and Shi'a fight like one person. There is no difference," one fighter told Vice News.

In short, there is no telling when Iraq will finally defeat ISIS militarily. However, what does seem indisputable is that the political inclusiveness under al-Abadi and his government's reforms of the security forces leaves the country much better poised to defeat the enemy than it was under the leadership of al-Maliki.