The Philippines has the geographical misfortune to be affected by 20 or so tropical cyclones a year, but what distinguishes the country as a disaster zone, apart from the resilience of its people, is the prevalence of guns and its long-running insurgencies. The attacks on aid convoys and the threat of violence hampering the humanitarian effort following Typhoon Haiyan amplify both problems.

Army officers have blamed several incidents this week on the New People's Army, the armed wing of the Communist Party of the Philippines. With its roots in peasant militias that fought the Japanese in the Second World War, the NPA's campaign is sometimes called the longest-running insurgency in the world, and has claimed an estimated 40,000 lives.

Opposing a weak independent post-war government, it evolved Maoist tendencies and spread throughout much of the archipelago, though it was strongest in central and southern islands. Offering an alternative to the dictatorship of Ferdinand Marcos, it peaked as a force in the 1980s, but remains active, especially in mountainous and neglected areas. The rebels are undoubtedly now in decline. The military aims to make Samar, one of the provinces worst affected by the typhoon, rebel-free, though such targets have been set before. In October, army commanders declared that rebel numbers in Leyte, which bore the brunt of Haiyan's fury, were down to a mere 40.

But areas once dominated by rebels remain flooded with weapons and it only takes a few men with a gun to spread panic among the hungry and the desperate, and to make life difficult for aid agencies. There are 3.9 million guns - legal and illegal - held by civilians in the Philippines. Although that is not especially high in global terms given a population of 107 million, the Philippines' murder rate is among the highest in Asia and three times that of the United States. Illegal guns are not just carried by criminal gangs and insurgents. They also belong to civilians and politicians who keep private armies.

Guns are so common that shops and restaurants commonly display signs asking customers not to bring their weapons inside. All private security guards carry either handguns or shotguns, or both. Analysts tend to blame the history of the Philippines for it becoming a gun-happy independent nation.

Three centuries of Spanish rule and machismo were followed by 50 years of American encouragement of the right to bear arms, making for a volatile mixture, it is said. Whatever the causes, the difficulties in distributing aid showed how, nearly 70 years after independence, central government has yet to impose itself fully throughout the archipelago of 80 provinces, dozens of languages and 7,000 islands.