ISTANBUL — Turkey intensified military strikes against Kurdish militants in northern Iraq on Wednesday, helicoptering in commandos and dropping bombs from the sky in its biggest operation on Iraqi soil in years to counter what it says are threats emanating from across the border.

The incursion is part of a far more assertive Turkish military policy that also has forces on the ground in Libya and Syria, revealing its go-it-alone inclination to tackle perceived threats that has increasingly put it at odds with traditional allies in NATO.

The latest offensive came just days after the Turkish armed forces launched another operation, dubbed Claw-Eagle, against the Kurdistan Workers Party (PKK), hitting 81 of its targets in Iraqi Kurdistan. Turkey has launched scores of cross-border attacks and air campaigns in hot pursuit of the guerrillas over the years and maintains several outposts in northern Iraq, but Wednesday’s offensive is the first large-scale air and land offensive inside Iraq in more than a decade.

“The Turkish Armed Forces began Operation Claw-Tiger against the PKK terrorist organization, which threatens the security of borders and people with increased harassment and attacks on outpost and base areas from Iraq’s north,” the Defense Ministry said on its website.