as the OP`s senario does not state any other action by the aliens other than " fly to washington airsapce and hover ... taking no further action "
then if i ran the zoo . then my measured and gradual response would be :
" move it or loose it " - my entire military would be put at condition one - so that if i need them , they are at maximum strengh and efficiency .
at the same time : the best and brightest : theologians , mathemeticians , philosophers , linguists , psycologists etc a classic " contact response
team " as hypothesised in books like "sphere " would be assembled and breifed .
i would want a two pronged response strategy of :
contain / attack [ if required ] - and approach / communicate -
both endeavours would have a degree of compartmentalisation - i would not have my negotiators / comminicaors aware of the tactical specifics of attack
if they do nothing - i am prepared to watch them too - unlessi have clear evidence that they are using the silence to deploy / ready an attack
i will gladdy let them sit there for a while .
as detailed below - every none invasive sensor i posess wuill be trained on them - and every scrap of data analysed in the most minute detail .
as the hypotherical alien has stopped [ by accident or design ] over the capital city of the worlds dominant super power - i would assume that if this
location was chosen - the occupants have studied the situation on earth sufficiently to be aware of the ligua franca and cultural leanings of the
people whoes attentions they have so spectacularly grabbed
if these " plain language " comunications fail to prompt a response - i would initate " from the basics up " math based communicatrion attempts to
try and reach a mutual logos .
plan / prepare
all the while - my military / inteligence and scientific community would be :
monitoring for further visitors - analusing any emmisions / radioation the craft emmits - for any inteligence which would assist in eithr
communication or attack strategies .
all the while , my government would be engaging in public awarness / evacuation planning and measures to maintain calm and order
the military would be tasked with conducting contingency planning - on how to attack it , with minimum civilian / infrastructure damage to washington
[ if required] -
i would have nukes , aircfaft , troops on a constant rotating " alert one " standby -
further resonse would require the alien craft to take further action / resopond to my initatives
PS Hank - ignore the idiot troll
and if you are preared to play this out - read this post and decide what the alien next move is -- i will respond