Complex sentence: The United States had pressured Pakistan for a military operation in North Waziristan for years, and the US Congress linked military assistance to Pakistan for the next fiscal year with military operations in North Waziristan in June 2014.
Split into simpler sentences: The United States had pressured Pakistan for a military operation in North Waziristan for years. The US Congress linked military assistance to Pakistan in the next fiscal year with military operations in North Waziristan in June 2014.