previous Texan attacks upon Laredo, to disrupt the economic development of the western frontier of Texas, and to strengthen the argument of the anti-annexationists in the United States that to annex Texas would be tantamount to annexing a war with a foreign power, Mexico in 1842 resumed the offensive by launching three invasions of Texas. In the fall of 1841, General Arista, the Centralist leader in the North, issued a manifesto, calling upon the Federalists and Centralists to forget their differences in the interest of greater harmony at home, and to give their attention to the real enemy. "In Texas," he declared, "there is a field open to gather fresh and glorious laurels that . . . false aspirations . . . calumny and envy cannot wither. In Texas you can find a field in which to display your warlike ardor without the pain and mortification of knowing that the blood you shed and the tears you occasion are from your brethren."[72]  From Monterey, Arista issued an address on January 9, 1842, to the inhabitants of the "Department of Texas," carefully pointing out the hopelessness of their struggle for independence and promising amnesty and protection to all who refrained from taking up arms during his contemplated invasion. At the same time he warned them that while his country held out "the olive branch and concord" with one hand, she would direct with the other "the sword of justice against the obstinate."[73]  Thereupon, Mexico began to strengthen her northern garrisons and to make preparations for invading Texas,[74]  but thoughtful persons in Texas believed Mexico