A traditional easing in fighting during the freezing winter months has been absent this year as the Taliban and Islamic State group respond to intensifying US and Afghan air assaults.
Since US President Donald Trump announced his new strategy for Afghanistan in August, giving the US Air Force more leeway to go after militants, American pilots have been bombarding Taliban and IS fighters, their training camps and drug-making laboratories.
The new policy has "definitely been a game-changer and the Taliban is definitely feeling it", he added.
The US is deploying more troops and aircraft to Afghanistan, which has become the main theatre of operations for the US Air Force following a drawdown in Syria and Iraq. At the same time it is beefing up Afghanistan's fledgling air capabilities.
More From This Section
US aircraft dropped 4,361 munitions across the country in 2017 -- including more than 2,300 since August, which exceeded the combined total for 2015 and 2016.
"The days of old where you had fighting seasons are gone," Major General James Hecker, head of NATO's Air Command in Afghanistan, told AFP in Kabul last week.
Militants have reacted violently to the increased airstrikes, launching a wave of deadly attacks across the war-torn country, including in Kabul, in a devastating display of defiance.
The Taliban, by far Afghanistan's biggest militant group, claimed 472 attacks last month alone, the Washington, DC-based terrorism research group TRAC said, describing the number as "unprecedented" for January.
The escalation of the conflict foreshadows a "particularly bloody year", Michael Kugelman of the Wilson Center in Washington, DC told AFP, forecasting more Afghan and US casualties.
Afghanistan's so-called "fighting season" traditionally starts in the spring before easing over the winter when freezing temperatures and heavy snow make combat more difficult.
But in recent years Taliban militants have continued to carry out attacks throughout the colder months.
"Afghanistan is suffering more intense violence now than during any other winter... since 2001," Osman said, highlighting last month's attacks in the Afghan capital that killed more than 130 people in less than 10 days.
Among the worst of the attacks was an assault on Kabul's luxury Intercontinental Hotel on January 20, a terrifying hours-long ordeal which saw Taliban insurgents armed with Kalashnikovs and suicide vests charge from room to room searching for foreigners.
That was followed a week later by a devastating bombing involving an explosives-packed ambulance in a crowded street that killed more than 100 people, mostly civilians, and also claimed by the Taliban.
The fighting this winter has been fuelled by more Taliban fighters remaining on the frozen battlefield instead of regrouping in Pakistan, which has long been accused of providing safe havens to the militants -- charges Islamabad denies.