It’s hard to believe that more than six years have passed since I was in Afghanistan’s Sangin Valley with British Royal Marines from 45 Commando.

The company I was embedded with was stationed at Forward Operating Base (FOB) Inkerman. Inkerman had something of a bad reputation back then and given the frequency of Taliban attacks had been nicknamed FOB ‘Incoming’.

At that time across Helmand Province all the way from Musa Qala to Lashkar Gah, Gereshk to Kajaki, British troops as part of coalition forces were taking the fight to the Taliban forcing them on to the back foot.

How things have changed in just a few short years. Only this week it was the Taliban who were on the advance, seizing an entire district of Helmand despite repeated US air strikes aimed at repelling them. These planes had been bombing Musa Qala since last weekend killing up to 40 militants, before the Taliban regrouped chasing the district government out of town and confiscating weapons in what a spokesman for Afghanistan's 215th Maiwand Corps called a "tactical retreat" to protect civilians.

The taking of Musa Qala after the Taliban overran Afghan police and army posts only added to the insurgents' recent advances in a heavily fought over region full of opium farms and trafficking routes. Only Last week, Afghan forces pulled out of the town of Nawzad, the headquarters of a neighbouring district that was also fiercely fought over when British and US forces were stationed in Helmand. To put these current developments into recent historical perspective, it’s worth remembering that more than 400 British soldiers died in Helmand, some while defending Musa Qala, while more than than 350 US Marines also lost their lives in the province. So what do these latest Taliban offensives tell us about the state of the insurgents’ operations across Afghanistan at the moment and does it suggest that the Afghan security forces without coalition support are not up to the job?

The first thing to realise here is that this year’s spring offensive and subsequent fighting season is the first where Afghan security forces have had to battle the Taliban pretty much on their own. Never slow on the tactical uptake, the Taliban appear to have caught Afghan forces off guard by initially focusing their attacks on the country’s northern provinces. This is something of a marked departure from previous tactical emphasis on their traditional strongholds in the south and east. Their northern push has allowed the Taliban to seize two vital districts that leaves them now less than 4 miles from the city of Kunduz. Not that the Afghan military was totally unprepared for this strenuous effort by the Taliban to gain substantial territory. This much was confirmed by Gen Mohammad Ayoub Salangi, Afghanistan’s deputy minister of interior for security, who warned in a recent interview that “the enemy had big plans for the year” and were clearly waiting for the pullout of coalition forces before launching attacks to capture several districts and possibly even provinces. Despite recent setbacks the good news in the short term at least is that all of Afghanistan’s 34 provincial capitals remain in government hands, as does the vast majority of district headquarters. So far so good one might say, but there is no escaping the serious concerns of many Afghans and outside analysts who fear this is only temporary and far from sustainable. For now Afghan forces have more than enough kit and military materiel to ensure they don’t fall apart immediately. Indeed last year a story emerged that the US military would leave behind equipment in Afghanistan valued at $6 billion. We are not talking about run-of-the-mill body armour and night vision goggles here, but the likes of hundreds of Mine-Resistant Ambush Protected vehicles (MRAPS) that have shielded American soldiers from improvised roadside bombs. The fate of all this equipment like Afghanistan itself remains unclear not least should President Barack Obama go ahead with his plan to withdraw almost all the remaining American troops next year.

After nearly 15 years of war, it is clear that the Taliban are far from exhausted in their struggle for power. Against old enemies and new threats, they continue to manoeuvre for a better position in Afghanistan's conflict.

In effect the group’s gains over this spring and summer have helped preserve its role as the primary opposition faction in the Afghan conflict, even as concerns about the Islamic State’s (IS) emergence in the region are growing. This latter point about the rise of IS is especially significant given that the Taliban has just undergone a leadership reshuffle that left it vulnerable to IS poaching recruits from among some of its younger fighters.

In the coming year, all eyes will be on Afghanistan’s fragile national unity government as it confronts this ferocious insurgency. Despite their recent victories in Mula Qasa in the south and around Kunduz in the north the Taliban still can’t boast of spectacular victories that have changed the course of the war. But, as time goes by, and US resources are inevitably cut back, questions remain over how long the Kabul government can keep up its resistance.

Just as I well remember being in Helmand six years ago, so too do I recall being in Afghanistan after the Soviets withdrew and the government in Kabul held out for more than three years before crumbling in a matter of weeks in 1992.

Unpalatable as it might be there is more than the possibility that history could well repeat itself. Afghanistan after all, is no stranger to such things.