Sid Caesar; native American rights; and more; Native American survival; Blood of the Land, by Rex Weyler. New York: Everest House. 304 pp. $16.95.

Now That the Buffalo's Gone, by Alvin M. Josephy Jr. New York: Alfred A. Knopf. 304 pp. $15.95.

The Indian Wars didn't end in the 1800s. Although the mood of the American public has changed from hatred to nostalgia, the engines of Western society are still geared to pulverize any remnants of Indian culture.

This is the message of these two new books about Indians.

In ''Blood of the Land,'' Rex Weyler sets the tone quickly. ''The events in this book,'' he writes, ''will show that the American and Canadian governments, the FBI, police forces, agents, courts, attorneys, and vigilantes are guilty of: murder, assault, theft, destruction of property, arson, perjury . . . and every imaginable sort of nastiness and depredation against the Indian people.''

Weyler, an associate publisher of New Age magazine, supports many of these charges with incidents that followed the birth of the American Indian movement in the 1960s. He insists, however, that ''the future lies not in guilt, but in a spiritual reawakening,'' by which he appears to mean that whites should adopt traditional Indian values toward nature and the land.

In ''Now That the Buffalo's Gone,'' Alvin M. Josephy Jr. sets out to educate, not exhort - as befits a former editor of American Heritage. He illustrates ''the present status, aims, and thinking of the American Indian'' by presenting them firmly in the context of history.

In the first part of the book, Josephy describes how Indians have struggled to maintain their unique identity, and how old stereotypes still influence their treatment by whites. In the second part, he chronicles their fight to retain Indian land and to reassert ancient treaty rights. In the last section, he explains the motivations behind today's growing push for Indian self-determination and sovereignty.

Weyler's book is angry and polemical; Josephy's is scholarly and cool. But the conclusions of each coincide to a surprising degree. This quote is from Josephy: ''Where Native Americans and Whites live near one another and Whites covet what the tribes still own, Indians of today know that there are continued racism and genocidal instincts. . . .''