Sri Lanka cannot armour-plate itself against these Tamil fanatics who are willing to blow themselves up along with whatever target their commanders select: a politician, a few generals, a president, oil depots, a naval vessel, and now dozens of innocent office workers. No country can, certainly not poor Sri Lanka, its treasury emptied by 12 years of civil war against the Tamil minority.
Other suicide bombers will undoubtedly be dispatched to Colombo by the Tamil Tigers' chief, Velupillai Prabhakaran, after he treats them to a final supper at his jungle hideout. It might be weeks before they arrive, or just days. But the residents of Colombo know they will come to kill.
The security forces in Colombo are tied down protecting government officials, most notably the President, Chandrika Kumaratunga, whose home is now a fortress ringed in barbed-wire and an anti-aircraft gun on the roof. Overstretched already, the police cannot protect Colombo's citizens. News agencies reported that hundreds fled Colombo yesterday, fearing that another suicide bomber might be stalking the city.
The easiest exit from this nightmare is for Mrs Kumaratunga to make peace with the Tamil rebels. The biggest obstacle to a deal has always been the Tigers' fanatical leadership, who have nothing to gain from peace. But for a few weeks after their defeat in Jaffna, hopes rose for a settlement. Not any longer, however. Few among the 400,000 Tamils who were made refugees by the fighting in Jaffna have returned to their area "liberated" by the government. Even if ordinary Tamils wanted to, the Tiger rebels will not allow them to go back to their towns and rice paddies.
Mrs Kumaratunga's strategy was to strike at the rebels and then offer a political solution: a devolution package which would give the predominately Tamil states in the north and east of the island more autonomy.
But extremists among the country's Sinhalese majority refuse to let her be generous to the Tamils. To get the devolution plan through parliament and then a referendum, she has watered it down so much that even moderate Tamils are backing away from her.
Under the new draft, Colombo will keep the right to dissolve the regional councils and police the regions, which the Tigers will never allow. Many of the Tamils, who are either Hindus or Christians, are also alarmed that the devolution package seems to give extra favours to the Sinhalese Buddhist clergy.
Militarily, the Tamil Tigers are far from defeated. Not only can they deploy their suicide bombers inside the heart of Colombo, but the Tiger commanders have stepped up their attacks along the eastern coast. Even in the supposedly secure Jaffna peninsula, Tiger sharpshooters were reported to have brought down one of the air force's few helicopters, killing all 39 people aboard. At one point, Mrs Kumaratunga was even prepared to offer Tamil rebels an amnesty, but after yesterday's massacre in Colombo, such a move would outrage the Sinhalese majority.