Question: Of the countries sharing a land border with Cambodia, which was a military combatant involved in the military conflict  the Vietnam War?
Answer(s):
answer: Thailand

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.01xbgx)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.01xbgx ns:location.location.adjoin_s ?y .
?y ns:location.adjoining_relationship.adjoins ?x .
?x ns:common.topic.notable_types ns:m.01mp .
?x ns:military.military_combatant.casualties ?c .
?c ns:military.casualties.military_conflict ns:m.07_nf . 
}