A great many journalists reporting on Israel-Palestine for US media have personal and family ties to the Israeli military. Many have served themselves; others have sons, husbands, etc. who are currently served in the IDF or have in the past.
This is a clear conflict of interest, but is virtually never voluntarily divulged – precisely because the journalists and the media know this is improper and would constitute a particularly blatant example of journalistic bias. For journalistic ethics' statements on this go here.
It is perhaps not surprising that David Brooks only revealed that his son was serving in the IDF to an Israeli newspaper – and that the newspaper only printed the information (somewhat buried) in its Hebrew-language edition, not in the English language edition that many people incorrectly assume contains all the articles in the paper.
I've written about this situation a number of times. Below are some of my articles:
Myra Noveck & the New York Times: Another journalist with children in the Israeli military
Jodi Rudoren, Another Member Of The Family: Meet The New York Times’ New Israel-Palestine News Chief
US Media and Israeli Military: All in the Family
Ethan Bronner's Conflict With Impartiality
Is "pundit" actually Israeli military officer?
AP’s Matti Friedman: Israeli citizen and former Israeli soldier