Question: Which nation involved in the 1991 Gulf War has maintained religious leadership since February 28, 1998?
Answer(s):
answer: Argentina

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.018w0j)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.018w0j ns:military.military_conflict.combatants ?y .
?y ns:military.military_combatant_group.combatants ?x .
?x ns:religion.religious_leadership_jurisdiction.leader ?c .
?c ns:religion.religious_organization_leadership.start_date "1998-02-28"^^xsd:dateTime . 
}