age : ▁person ▁or ▁groups ▁such ▁as ▁ex - emp loy ees , ▁anti - g overn ment ▁groups , ▁environmental ▁groups . ▁Refer ▁to ▁Bang k ok ' s ▁International ▁Airport ▁Se ized ▁by ▁Protest ors . ▁ ▁Information ▁war fare : ▁private ▁person ▁hack ing ▁for ▁private ▁gain ▁or ▁countries ▁initi ating ▁attacks ▁to ▁g lean ▁information ▁and ▁damage ▁a ▁country ' s ▁cy ber ▁infrastr ucture . ▁Cy ber att acks ▁on ▁Est onia ▁and ▁cy ber att acks ▁during ▁the ▁ 2 0 0 8 ▁South ▁Os set ia ▁war ▁are ▁examples . ▁ ▁Natural ▁dis aster : ▁h urr icane ▁or ▁other ▁natural ▁events ▁which ▁damage ▁critical ▁infrastr ucture ▁such ▁as ▁oil ▁pip elines , ▁water ▁and ▁power ▁gr ids . ▁See ▁H urr icane ▁I ke ▁and ▁Econom ic ▁effects ▁of ▁H urr icane ▁K atr ina ▁for ▁examples . ▁ ▁Iss ues ▁in ▁national ▁security ▁ ▁Cons ist ency ▁of ▁approach ▁ ▁The ▁dimensions ▁of ▁national ▁security ▁out lined ▁above ▁are ▁frequently ▁in ▁t ension ▁with ▁one ▁another . ▁For ▁example : ▁ ▁The ▁high ▁cost ▁of ▁maintain ing ▁large ▁military ▁forces ▁places ▁a ▁bur den ▁on ▁the ▁economic ▁security ▁of ▁a ▁nation . ▁The ▁share ▁of ▁government ▁exp end iture ▁on ▁state ▁armed ▁forces ▁var ies ▁intern ation ally ; ▁for ▁example , ▁in ▁ 2 0 1 5 ▁it ▁was ▁ 4 % ▁in ▁Germany , ▁ 9 % ▁in ▁Chile , ▁ 1 4 % ▁in ▁the ▁USA , ▁ 1 5 %