President Yoweri Museveni has ordered security agencies to re-introduce military training for Ugandan civilians to counter the threat from al-Shabab.
Writing in the state-owned New Vision newspaper, Mr Museveni said that although al-Shabab was “defeated”, Ugandans need to guard against attacks.
Uganda has more than 6,000 troops in Somalia as part of an African Union force battling the Islamist militants.
In 2010, al-Shabab bomb attacks in Kampala killed at least 76 people.
Catherine Byaruhanga, BBC News, Kampala
In his open letter, President Museveni focuses on al-Shabab, calling them “idiots”.
But the threat of attack from the Islamist militants is not the only source of insecurity for Ugandans. As the Ugandan army spokesman told the BBC, al-Shabab are not the only targets of this policy.
In the past few months, security has become a bigger concern than usual in Uganda.
In December, two Muslim clerics were shot dead in the capital Kampala, and in March, the top state prosecutor, who was investigating the 2010 al-Shabab attack,was shot and killed on her way home from work.
It is still unclear who is responsible for the killings and whether they are linked.
It is also far from certain that military education for civilians would help keep Uganda safe.
In the 1980s and 1990s, Ugandan school leavers used to perform two years of national service before attending university.
President Museveni said he had already given instructions to the relevant security agencies to launch the programme, focusing initially on the most vulnerable areas in the country.
He did not give many details about the scheme, but Ugandan army spokesman Lt Col Paddy Ankunda said that there were no plans to arm the civilian population.