military blockade vs besieging

military blockade and besieging both are nouns.

Word	Noun	Adjective	Verb	Adverb
military blockade	Yes	No	No	No
besieging	Yes	No	No	No

As nouns, military blockade and besieging are synonyms defined as:

military blockade and besieging: the action of an armed force that surrounds a fortified place and isolates it while continuing to attack

Other synonyms of military blockade include beleaguering, siege.

military blockade (noun)	besieging (noun)
the action of an armed force that surrounds a fortified place and isolates it while continuing to attack	the action of an armed force that surrounds a fortified place and isolates it while continuing to attack