It is still common for nations, including the united states, to sign defense treaties. do you think this is important? why?

Yes it is important. Mutual defence treaties are a very powerful diplomatic tool in diplomacy. Countries use defence treaties as a deterent against other countries. There is strength in numbers. By signing such treaties a potentially hostile country must look at the help others will recieve if it acts aggressively.

a. the astrolabe could determine the correct latitudinal location of the ship

states

explanation:

as the old saying goes, all politics are local. state and federal governments affect our daily lives in numerous ways. yet, in our federal system, there is supposed to be a balance between federal and state power. as james madison envisioned it in federalist no. 51, “the power surrendered by the people” would be “divided between two distinct governments,” creating a balance of power that would enable the “different governments [to] control each other.”