World leaders there; United States leaders absent…
Check it out:

Sunday’s massive march in Paris against terrorism drew dozens of world leaders in a show of unity — except from the United States, which was represented by its ambassador.

US Attorney General Eric Holder, who was in Paris Sunday to attend a meeting of interior and justice ministers discussing measures to combat jihadist attacks, was meant to have participated in the rally according to the White House on Saturday, but did not do so, the US embassy in Paris confirmed.

The embassy did not say why Holder did not attend the march. It said the United States was represented in the huge rally by its ambassador to France, Jane Hartley.