The Philippine government may not like to admit it, but resolving its conflict with Muslim groups on the country's southern islands is an uncomplicated matter. The argument is essentially about land. President Gloria Macapagal-Arroyo, like leaders before her, believes that national unity is foremost. She has denied Muslims their claim to absolute authority over territory that was previously part of Islamic kingdoms. Since independence from the US in 1946, the problem has grown from successive governments' exertion of national identity. Starting in the 1950s, transmigration from Catholic areas to religiously dilute the Muslim-majority islands of Mindanao, Basilan and Sulu has fuelled discontent. Modern economic and legal systems have complicated the affair. Land has become an important status symbol for Christians, but many Muslim communities still espouse the centuries-old practice of clan ownership. This has been a fundamental sticking point in negotiations between the government and the dominant separatist group, the Moro Islamic Liberation Front (MILF). Peace was sealed with another group, the Moro National Liberation Front, by former president Fidel Ramos, and the Autonomous Region of Muslim Mindanao established. Tens of thousands have died in decades of fighting between the military and groups like the MILF and Abu Sayyaf. At least 21 were killed on Tuesday in Mindanao's biggest city, Davao, by a bomb placed by suspected Muslim extremists. Before September 11, the government referred to such incidents as the work of separatists or bandits. Now, Mrs Arroyo, her officials and the military have politicised the issue, calling them terrorists. Although the terminology has changed, the objectives of Muslims have not. Neither has the government altered its resolve. With such thinking, getting the US involved was natural. As many as 1,000 American troops have been in the country for the past year, ostensibly to train the Philippine military, and they are being joined by up to 2,000 more frontline soldiers. The conflict is indigenous and cannot be solved by foreign intervention. Negotiation, not hi-tech military equipment, must be the means. As with the US-led war on Iraq, the Philippines risks inviting a Muslim backlash rather than achieving unity.