As Par and Gadet battled each other, the Sudanese government exploited the inter-rebel conflict as part of a divide and rule strategy, aimed at weakening the rebellion at large and allowing for the extraction of valuable oil in Unity State.

Following its independence in 1956, the Sudan had suffered from numerous internal conflicts over political, ethnic, economic, and religious issues.

Many southern Sudanese outright opposed the group for a variety of reasons, and instead sided with the government or set up rival insurgent movements.

[6] Two prominent SPLA commanders, Riek Machar and Lam Akol, attempted to overthrow Garang in an unsuccessful coup in 1991.

[8] The Sudanese government increasingly focused on clearing areas in the south for oil extraction instead of winning the war, as it was in desperate need of cash.

The SSDF was an umbrella organization for several armed factions, including Machar's loyalists and the troops of warlords like ex-Anyanya II leader Paulino Matip Nhial.

The government responded by launching a campaign to drive away civilians and Machar's troops from drilling locations in Block 5A such as Thar Jath.

[16] In response, Machar's local loyalists under Tito Biel and Peter Par Jiek aligned with the SPLA and counterattacked.

He subsequently unified his force with the militias of other regional warlords such as Biel and Par to form the "Upper Nile Provisional United Military Command Council".

[26] The situation changed once again in February 2000, when Machar openly broke with the government, fully left the SSDF, and founded the SPDF rebel group.

[29] Despite the tensions and opposing political alignments, cooperation mostly continued until the Sudanese government launched another major offensive in Unity State in April 2000.

[1] The SPLA argued that Par had executed 22 fighters loyal to Gadet in December 1999 and June 2000, and forged an alliance with the Sudanese government.

Matip's SSDF militia began to openly fight alongside Par's men,[33] and the latter also guarded government installations, especially the oil extraction facilities of Thar Jath in Block 5A.

[38] When they captured Koch, Gadet's men killed two health workers and stole the local clinic's medical supplies.

To avoid war between them, Machar sent Biel to Maiwut County where he was supposed to rally Jikany Nuer to the SPDF's cause.

[41][42] Many civilians fled to Bahr el Ghazal,[39] and although hunger and disease spread among the refugees,[43] most subsequently chose to stay as their old homes had been destroyed.

[47] Gadet's troops attacked the United Nations relief hub of Nyal inside SPDF territory in February 2001.

This almost resulted in a further escalation, as the attack was regarded as breach of an earlier peace agreement between Nuer and Dinka militias that was still partially in effect.

A few months later, Machar came to an understanding with the SPLA leadership and agreed to merge the SPDF with SPLA-Mainstream, whereupon Par and Gadet signed a final peace agreement in Koch in February 2002.

Lundin Petroleum suspended operations at Thar Jath, forcing the government to launch new costly offensives in Unity State in 2002.

In particular, Gadet would play out the SPLA and the government against each other to gain power,[23] and eventually fully defected back to the pro-government forces.