comma and period after 'U.S.' [abbreviation]: with the U.S., and this

[teacup2]

Hello!

I am reading an academic thesis, and the author consistently uses the abbreviation "U.S." to denote the United States. My question is, is it correct to add a comma after the full stop, as in:
"Mao was against Khrushchev’s ‘peaceful coexistence’ with the U.S., and this contributed to the problematic relationship between China and the Soviet Union."

Furthermore, the same author uses a full stop to end a sentence after having used a full stop in "the U.S."! Is this correct usage/punctuation?
"Propaganda has not been understood in the negative sense that it has in Europe and the U.S.."

Many thanks in advance,
Elinor

 

[kalamazoo]

I think "U.S.," is okay, but not "U.S.."

 

[Egmont]

The comma after "U.S." is correct because it indicates a break in the sentence. Suppose it were "Mao was against Khrushchev's 'peaceful coexistence' with England, and this ..." It's the same structure, so the comma is equally correct.

When an abbreviation ends a sentence, the same period (BE "full stop") serves two purposes. Using two is just an error.

 

[teacup2]

Sincere thanks to you both!

 

[sdgraham]

I think the United States should have been written out in the first place if this indeed is an academic paper.

And no, you never use two periods together unless part of an ellipsis.

 

[teacup2]

That's true. And thanks for the new term, 'ellipsis'!

 

[natkretep]

Just confirming that the <.,> combination is possible (as in i.e.,) but not the <..> one (unless this is ellipsis, as pointed out by sdgraham). The tendency in many publications, particularly in BE style, is to omit the stops (periods) for initialisms, so the issue does not arise.

 

[Egmont]

...but not the <..> one (unless this is ellipsis, as pointed out by sdgraham)...

However, an ellipsis should never be only two periods. It should be three. Granted, there are two periods in a row within it, but the third must always be present as well.

 

[natkretep]

However, an ellipsis should never be only two periods. It should be three. Granted, there are two periods in a row within it, but the third must always be present as well.

I agree. Ellipsis is generally with three dots. The only place where I have seen the two-dot ellipsis is the Oxford English Dictionary - presumably to save space?