What issues were at stake for the United States in El Salvador and Nicaragua?History 2

Time frame is important with this question, as we have
been involved in those countries for quite some time.  I am assuming, since you chose
those two in particular, that you mean our involvement with them in the 1970s and 80s
when there were revolutions/rebellions in both.

At that
time, the Cold War was still going strong, and as many times before, we had allied
ourselves with sometimes brutal dictatorships in order to protect US business interests
there and to keep those countries non-communist.  To be clear, there was little threat
to actual US national security if either of these countries actually had gone
communist.  They have little in the way of resources or exports that we need or needed. 
Companies like United Fruit and others, however, had large tracts of land ownership, and
had for decades put pressure on the US government to protect their interests
there.

In a larger social and political sense, Presidents
Jimmy Carter and Ronald Reagan did not want to seem soft on communism and have the red
shade of the globe expanded on their watch, so we gave large amounts of military aid to
both countries - in El Salvador to fight the FMLN communist rebels, and in Nicaragua to
try and save the Somoza regime, and when that failed, to fund a rebellion known as the
Contras.

In summary, business interests mostly, but also
larger Cold War containment and political image issues at home.