The claim states that certain practices undermine ceasefire agreements and international law, threatening Lebanon's sovereignty. Two web search results discuss the existence and terms of Israel-Lebanon cease-fire agreements, indicating such agreements and potential violations are topics of discussion. However, no single source directly makes the sweeping claim that 'these practices actually undermine both ceasefire agreements and established principles of international law, threatening Lebanon's sovereignty' in a way that can be corroborated by multiple independent sources. The evidence is suggestive but not conclusive enough for 'corroborated' status.

The claim asserts that Nadim Houry argues the doctrine is a legal façade for expanding occupation using self-defense language, citing Gaza, Syria, and Lebanon. One web search result mentions Houry discussing the 'Yellow line doctrine' in the context of Lebanon, but the evidence provided does not contain multiple independent sources confirming the specific argument about it being a 'legal façade' citing Gaza, Syria, and Lebanon. The other evidence provided is irrelevant (Wikipedia entries on Enforced disappearance, IS, or War crimes in Syria).

The claim attributes the statement to Nadim Houry regarding the 'Yellow Line doctrine' being a military tool rather than a security measure. While one web search result quotes Houry making a statement about the 'Yellow line doctrine' and demolition, no other independent sources corroborate this specific characterization or attribution. The other evidence provided is irrelevant (Wikipedia entries on Flagellation, Ba'athist Syria, or Shamaa).