Synonyms for Countering:

adj.

defensive (adjective)
guarded, cautious, defensive, buffering, guarding, wary, armored, protective, secure, Sheltering, shielding.

v.

answering (verb)
expounding, Acknowledging, answering, Rebutting, countercharging, coming back, Retorting, echoing, Replying, Explaining, Responding, returning.
defending (verb)
guarding, Securing, Warding, upholding, opposing, averting, counterattacking, screening, Policing, supporting, buffering, barring, safeguarding, defending, shielding, Sheltering, Sustaining, backfiring, protecting, covering, Barricading, arguing, Fending, saving.
defying (verb)
Counteracting, Resisting, daring, confronting, challenging, Affronting, Countermanding, crossing, Defying, Contravening, facing, rebelling, dissenting.
hindering (verb)
Bunging, Crimping, Hamstringing, stopping, thwarting, Fouling, Snagging, fettering, catching, Handicapping, Burdening, bottlenecking, Cramping, Complicating, restricting, dragging, Interrupting, choking, Encumbering, baffling, curbing, constraining, Impairing, Plugging, Clogging, jamming, Snarling, Damming, crippling, Tangling, Detaining, Deterring, Paralyzing, Miring, Hampering, Restraining, blocking, Entangling, braking, Delaying, constipating, Staying, frustrating, congesting, Entrapping.
opposing (verb)
conflicting, Suppressing, repressing, Checking, protesting, Rebuffing, Contradicting, impeding, meddling, Disputing, Intercepting, Obstructing, hindering, Oppressing, repelling, inhibiting, interfering, disagreeing, antagonizing, Objecting, fighting, Repulsing.
retaliating (verb)
returning fire, Repaying, reprising, Revenging, reciprocating, Retaliating, redressing, avenging, Exchanging.