washington u.s. secretary defense jam mattis week ask congress halt pending legislation would compel u.s. alert foreign governments pentagon decide combat certain cyber attack accord letter send lawmakers letter send members congress tuesday see reuters come lawmaker finalize department defense 2018 spend plan also know national defense authorization act fiscal year 2018 ndaa nature cyber-attacks ever evolve need maintain ability take decisive action increasingly dangerous threat mattis write language draft ndaa say cyber attack transit third party country infrastructure rely upon network u.s. encourage nation take action eliminate threat however draft ndaa say u.s. reserve right act unilaterally need mattis letter dub heartburn letter highlight pentagon concern budget often use previous pentagon chiefs attempt influence lawmakers legislation still consideration letter mattis repeat early request congress consider close base 2021 estimate save billion annually congress fearful economic impact base close district generally sympathetic efforts mattis also say oppose formation additional military service dub space corps call additional organizational layer space corps would new military branch absorb air force military efforts space u.s. senate pass version 700 billion defense policy bill september back president donald trump call big strong military set stage battle government spend level house representatives pass version ndaa similar spend level july two versions reconcile congress consider final version fight spend expect senate democrats vow block big increase fund military spend cap non-defense program ease well two versions bill increase military spend well beyond current spend cap allow pentagon chief ask congress hind cyber defense