A sound not heard for many years just came across Uzbekistan's southern border -- the sound of rocket fire from Afghanistan.
Afghanistan's Ariana TV reported that the Taliban attacked an Afghan border post in the Kaldor district of Balkh Province during the night of May 2. Ariana showed General Mir Hayma Haidari saying the attack was beaten back and there were no casualties among Afghan government troops.
That probably won't be much consolation for Uzbek President Islam Karimov. He knows where Kaldor district is located: just east of Uzbekistan's southernmost city of Termez, the gateway to Afghanistan.
Rockets from fighting in Afghanistan hit Termez in September 1997. When the Taliban captured the Afghan border town of Hairaton, in Kaldor district, in August 1998, it sparked panic in the Uzbek capital. Hairaton is on the other side of the river that divides Uzbekistan and Afghanistan, the Amu-Darya. Karimov personally went to Termez just days after Hairaton's capture to assess the situation.
Uzbekistan and President Karimov had to live with the Taliban at the doorstep for three years. Karimov was among the happiest of people when the United States started its military campaign in Afghanistan in the wake of the terrorist attacks on New York and Washington in September 2001 and chased the Taliban from the area.
But in the last few years the Taliban has made its way back and spread out across northern Afghanistan. Afghan fighting has reached the borders of both Tajikistan and Turkmenistan, Uzbekistan's Central Asian neighbors, in recent months.
Uzbekistan had been spared because there was relative calm in Balkh Province. Until this year. Since March, government forces in Balkh have been busy clearing districts of Taliban fighters. But as of May 2, the Taliban was clearly still present in the district of Kaldor.
Balkh Governor Atta Mohammad Nur said in March that there were not only Taliban militants in his province but fighters loyal to the extremist group Islamic State. These latter militants might be remnants of the Islamic Movement of Uzbekistan, sent to northwestern areas of Afghanistan by their leader, Usman Ghazi, after he swore allegiance to Islamic State and before Ghazi was killed in November 2015.
Uzbekistan has another complication to consider. There is a long-standing rivalry for power in Balkh between Governor Nur and Vice President Abdul Rashid Dostum. For much of the last 30 years, the provincial capital -- Mazar-e Sharif -- was Dostum's stronghold.
Dostum has come to personally lead operations against the Taliban in provinces to the west of Balkh (Baghdis and Faryab) four times since the summer of 2015, an effort on which the two former warlords have professed unity. However, competing rallies by supporters of Nur and Dostum in Mazar-e Sharif in late March raised tensions in the city and worried officials in Kabul. So there is the danger of infighting between Nur and Dostum that would leave the border with Uzbekistan vulnerable on the Afghan side.
This already happened once, in 1997, when Abdul Malik, one of Dostum's commanders, rebelled and chased Dostum from the region. Malik then announced he was siding with the Taliban and invited the militants into Mazar-e Sharif, where Malik then switched sides again and massacred large numbers of Taliban fighters.
Dostum eventually ousted Malik and regained control, but his greatly weakened forces were no match for the Taliban, who returned in August 1998 and had little trouble capturing Mazar-e Sharif.
Further complicating the situation for President Karimov is that during the 1990s Uzbekistan supported Dostum, providing Mazar-e Sharif with free electricity, and possibly much more. Tashkent saw Dostum as the guardian of the gates to Uzbekistan.
One couldn't blame Nur for wondering not only about Dostum's intentions, but Tashkent's as well.
Uzbekistan's side of the border has been fortified and refortified over the course of two decades. Reportedly, Uzbekistan just sent more forces to the border with Afghanistan in April after Uzbek border guards were involved in shootouts that left three Afghan nationals dead. There is no possibility of any force making a successful incursion across the Amu-Darya into Uzbekistan.
But the May 2 rocket attack on an Afghan border post could very well feed the Uzbek government's paranoia about its own population and potential enemy sympathizers. Uzbekistan's citizens know what that means; many remember well the mass arrests of the late 1990s when the Taliban last made its way to the Uzbek border.
With contributions from RFE/RL Uzbek Service Director Alisher Sidik