Using this nice code from here:
countries <- structure(list(country = structure(c(5L, 6L, 3L, 4L, 10L, 8L, 11L, 7L, 1L, 13L, 9L, 12L, 2L), .Label = c(\"A
You're missing the data parameter in your geom_text:
data
geom_text
p + geom_text(data = countries, aes(label=Value, x=Longitude, y=Latitude), hjust=0, vjust=0)